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    <link:label xlink:label="intt_statement-statement-note-2-summary-of-significant-accounting-policies-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 2 - Summary of Significant Accounting Policies</link:label>
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    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-3-restructuring-and-other-charges-tables" xlink:label="intt_statement-statement-note-3-restructuring-and-other-charges-tables" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-3-restructuring-and-other-charges-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 3 - Restructuring and Other Charges</link:label>
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    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Risk-free interest rate</link:label>
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    <link:label xlink:label="intt_statement-statement-note-4-goodwill-and-intangible-assets-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 4 - Goodwill and Intangible Assets</link:label>
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    <link:label xlink:label="intt_statement-statement-note-5-revenue-from-contracts-with-customers-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 5 - Revenue From Contracts With Customers</link:label>
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    <link:label xlink:label="intt_statement-statement-note-7-inventories-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 7 - Inventories</link:label>
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    <link:label xlink:label="intt_statement-statement-note-8-leases-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 8 - Leases</link:label>
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    <link:label xlink:label="intt_statement-statement-note-9-other-current-liabilities-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 9 - Other Current Liabilities</link:label>
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    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-10-debt-tables" xlink:label="intt_statement-statement-note-10-debt-tables" xlink:type="locator"/>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income Tax Disclosure [Text Block]</link:label>
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    <link:label xlink:label="intt_statement-statement-note-11-income-taxes-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 11 - Income Taxes</link:label>
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    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-13-stockbased-compensation-plan-tables" xlink:label="intt_statement-statement-note-13-stockbased-compensation-plan-tables" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-13-stockbased-compensation-plan-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 13 - Stock-based Compensation Plan</link:label>
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    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-16-segment-information-tables" xlink:label="intt_statement-statement-note-16-segment-information-tables" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-16-segment-information-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 16 - Segment Information</link:label>
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    <link:label xlink:label="intt_statement-statement-note-17-quarterly-consolidated-financial-data-unaudited-tables-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 17 - Quarterly Consolidated Financial Data (Unaudited)</link:label>
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    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Expected common stock market price volatility factor</link:label>
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    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-schedule-ii-valuation-and-qualifying-accounts-tables" xlink:label="intt_statement-statement-schedule-ii-valuation-and-qualifying-accounts-tables" xlink:type="locator"/>
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    <link:label xlink:label="us-gaap_LiabilitiesCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LiabilitiesCurrent</link:label>
    <link:label xlink:label="us-gaap_LiabilitiesCurrent-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total current liabilities</link:label>
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    <link:label xlink:label="intt_AutomobileLeasesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Automobile Leases [Member]</link:label>
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    <link:label xlink:label="us-gaap_OtherLiabilitiesCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other current liabilities</link:label>
    <link:label xlink:label="us-gaap_OtherLiabilitiesCurrent-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total other current liabilities</link:label>
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    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Weighted average expected life of stock options (years) (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1-label" xlink:type="arc"/>
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    <link:label xlink:label="intt_statement-statement-note-4-goodwill-and-intangible-assets-changes-in-the-amount-of-the-carrying-value-of-intangible-assets-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 4 - Goodwill and Intangible Assets - Changes in the Amount of the Carrying Value of Intangible Assets (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-4-goodwill-and-intangible-assets-changes-in-the-amount-of-the-carrying-value-of-intangible-assets-details" xlink:to="intt_statement-statement-note-4-goodwill-and-intangible-assets-changes-in-the-amount-of-the-carrying-value-of-intangible-assets-details-label" xlink:type="arc"/>
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    <link:label xlink:label="intt_statement-statement-note-4-goodwill-and-intangible-assets-intangible-assets-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 4 - Goodwill and Intangible Assets - Intangible Assets (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-4-goodwill-and-intangible-assets-intangible-assets-details" xlink:to="intt_statement-statement-note-4-goodwill-and-intangible-assets-intangible-assets-details-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-4-goodwill-and-intangible-assets-future-amortization-expense-details" xlink:label="intt_statement-statement-note-4-goodwill-and-intangible-assets-future-amortization-expense-details" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-4-goodwill-and-intangible-assets-future-amortization-expense-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 4 - Goodwill and Intangible Assets - Future Amortization Expense (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-4-goodwill-and-intangible-assets-future-amortization-expense-details" xlink:to="intt_statement-statement-note-4-goodwill-and-intangible-assets-future-amortization-expense-details-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_AllowanceForDoubtfulAccountsReceivableForeignCurrencyTranslation" xlink:label="intt_AllowanceForDoubtfulAccountsReceivableForeignCurrencyTranslation" xlink:type="locator"/>
    <link:label xlink:label="intt_AllowanceForDoubtfulAccountsReceivableForeignCurrencyTranslation-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_AllowanceForDoubtfulAccountsReceivableForeignCurrencyTranslation</link:label>
    <link:label xlink:label="intt_AllowanceForDoubtfulAccountsReceivableForeignCurrencyTranslation-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Foreign currency translation adjustments</link:label>
    <link:label xlink:label="intt_AllowanceForDoubtfulAccountsReceivableForeignCurrencyTranslation-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of foreign currency translation gain (loss) which (increases) decreases allowance for credit loss on accounts receivable.</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-5-revenue-from-contracts-with-customers-disaggregation-of-revenues-details" xlink:label="intt_statement-statement-note-5-revenue-from-contracts-with-customers-disaggregation-of-revenues-details" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-5-revenue-from-contracts-with-customers-disaggregation-of-revenues-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 5 - Revenue From Contracts With Customers - Disaggregation of Revenues (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-5-revenue-from-contracts-with-customers-disaggregation-of-revenues-details" xlink:to="intt_statement-statement-note-5-revenue-from-contracts-with-customers-disaggregation-of-revenues-details-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-5-revenue-from-contracts-with-customers-changes-in-allowance-for-doubtful-accounts-details" xlink:label="intt_statement-statement-note-5-revenue-from-contracts-with-customers-changes-in-allowance-for-doubtful-accounts-details" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-5-revenue-from-contracts-with-customers-changes-in-allowance-for-doubtful-accounts-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 5 - Revenue From Contracts With Customers - Changes in Allowance for Doubtful Accounts (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-5-revenue-from-contracts-with-customers-changes-in-allowance-for-doubtful-accounts-details" xlink:to="intt_statement-statement-note-5-revenue-from-contracts-with-customers-changes-in-allowance-for-doubtful-accounts-details-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-7-inventories-inventories-held-details" xlink:label="intt_statement-statement-note-7-inventories-inventories-held-details" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-7-inventories-inventories-held-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 7 - Inventories - Inventories Held (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-7-inventories-inventories-held-details" xlink:to="intt_statement-statement-note-7-inventories-inventories-held-details-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-8-leases-lease-costs-details" xlink:label="intt_statement-statement-note-8-leases-lease-costs-details" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-8-leases-lease-costs-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 8 - Leases - Lease Costs (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-8-leases-lease-costs-details" xlink:to="intt_statement-statement-note-8-leases-lease-costs-details-label" xlink:type="arc"/>
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    <link:label xlink:label="intt_statement-statement-note-8-leases-maturities-of-lease-liabilities-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 8 - Leases - Maturities of Lease Liabilities (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-8-leases-maturities-of-lease-liabilities-details" xlink:to="intt_statement-statement-note-8-leases-maturities-of-lease-liabilities-details-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-8-leases-lease-modifications-details" xlink:label="intt_statement-statement-note-8-leases-lease-modifications-details" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-8-leases-lease-modifications-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 8 - Leases - Lease Modifications (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-8-leases-lease-modifications-details" xlink:to="intt_statement-statement-note-8-leases-lease-modifications-details-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-9-other-current-liabilities-other-current-liabilities-details" xlink:label="intt_statement-statement-note-9-other-current-liabilities-other-current-liabilities-details" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-9-other-current-liabilities-other-current-liabilities-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 9 - Other Current Liabilities - Other Current Liabilities (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-9-other-current-liabilities-other-current-liabilities-details" xlink:to="intt_statement-statement-note-9-other-current-liabilities-other-current-liabilities-details-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement, Option, Activity [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-10-debt-outstanding-letters-of-credit-details" xlink:label="intt_statement-statement-note-10-debt-outstanding-letters-of-credit-details" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-10-debt-outstanding-letters-of-credit-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 10 - Debt - Outstanding Letters of Credit (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-10-debt-outstanding-letters-of-credit-details" xlink:to="intt_statement-statement-note-10-debt-outstanding-letters-of-credit-details-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-11-income-taxes-earnings-before-income-taxes-details" xlink:label="intt_statement-statement-note-11-income-taxes-earnings-before-income-taxes-details" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-11-income-taxes-earnings-before-income-taxes-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 11 - Income Taxes - Earnings Before Income Taxes (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-11-income-taxes-earnings-before-income-taxes-details" xlink:to="intt_statement-statement-note-11-income-taxes-earnings-before-income-taxes-details-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent</link:label>
    <link:label xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Foreign currency translation adjustments</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:to="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent-label" xlink:type="arc"/>
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    <link:label xlink:label="intt_statement-statement-note-11-income-taxes-income-tax-expense-benefit-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 11 - Income Taxes - Income Tax Expense (Benefit) (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-11-income-taxes-income-tax-expense-benefit-details" xlink:to="intt_statement-statement-note-11-income-taxes-income-tax-expense-benefit-details-label" xlink:type="arc"/>
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    <link:label xlink:label="intt_statement-statement-note-11-income-taxes-deferred-tax-assets-and-liabilities-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 11 - Income Taxes - Deferred Tax Assets and Liabilities (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-11-income-taxes-deferred-tax-assets-and-liabilities-details" xlink:to="intt_statement-statement-note-11-income-taxes-deferred-tax-assets-and-liabilities-details-label" xlink:type="arc"/>
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    <link:label xlink:label="intt_statement-statement-note-11-income-taxes-effective-tax-rate-analysis-and-reconciliation-of-expected-statutory-rate-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 11 - Income Taxes - Effective Tax Rate Analysis and Reconciliation of Expected Statutory Rate (Details)</link:label>
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    <link:label xlink:label="intt_statement-statement-note-13-stockbased-compensation-plan-allocation-of-sharebased-compensation-expense-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 13 - Stock-based Compensation Plan - Allocation of Share-based Compensation Expense (Details)</link:label>
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    <link:label xlink:label="intt_statement-statement-note-13-stockbased-compensation-plan-stock-option-activity-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 13 - Stock-based Compensation Plan - Stock Option Activity (Details)</link:label>
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    <link:label xlink:label="intt_statement-statement-note-13-stockbased-compensation-plan-unvested-stock-activity-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 13 - Stock-based Compensation Plan - Unvested Stock Activity (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-13-stockbased-compensation-plan-unvested-stock-activity-details" xlink:to="intt_statement-statement-note-13-stockbased-compensation-plan-unvested-stock-activity-details-label" xlink:type="arc"/>
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    <link:loc xlink:href="intt-20201231.xsd#intt_statement-statement-note-16-segment-information-segment-information-details" xlink:label="intt_statement-statement-note-16-segment-information-segment-information-details" xlink:type="locator"/>
    <link:label xlink:label="intt_statement-statement-note-16-segment-information-segment-information-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 16 - Segment Information - Segment Information (Details)</link:label>
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    <link:label xlink:label="intt_statement-statement-note-16-segment-information-identifiable-assets-details-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Note 16 - Segment Information - Identifiable Assets (Details)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_statement-statement-note-16-segment-information-identifiable-assets-details" xlink:to="intt_statement-statement-note-16-segment-information-identifiable-assets-details-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_FacilitySizeReductionMember" xlink:label="intt_FacilitySizeReductionMember" xlink:type="locator"/>
    <link:label xlink:label="intt_FacilitySizeReductionMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Facility Size Reduction [Member]</link:label>
    <link:label xlink:label="intt_FacilitySizeReductionMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to the facility reduction in size.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_FacilitySizeReductionMember" xlink:to="intt_FacilitySizeReductionMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameAxis" xlink:label="us-gaap_RetirementPlanNameAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RetirementPlanNameAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Retirement Plan Name [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetirementPlanNameAxis" xlink:to="us-gaap_RetirementPlanNameAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="us-gaap_RetirementPlanNameDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RetirementPlanNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Retirement Plan Name [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetirementPlanNameDomain" xlink:to="us-gaap_RetirementPlanNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Options outstanding, weighted average exercise price (in dollars per share)</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Options outstanding, weighted average exercise price (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Customer deposits and deferred revenue</link:label>
    <link:label xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ContractWithCustomerLiabilityCurrent</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiabilityCurrent" xlink:to="us-gaap_ContractWithCustomerLiabilityCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Canceled, weighted average exercise price (in dollars per share)</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Goodwill and Intangible Assets Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:to="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfGoodwillTextBlock" xlink:label="us-gaap_ScheduleOfGoodwillTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfGoodwillTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Goodwill [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfGoodwillTextBlock" xlink:to="us-gaap_ScheduleOfGoodwillTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Granted, weighted average exercise price (in dollars per share)</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxesPayableCurrent" xlink:label="us-gaap_TaxesPayableCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TaxesPayableCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Domestic and foreign income taxes payable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TaxesPayableCurrent" xlink:to="us-gaap_TaxesPayableCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrued wages and benefits</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeasesTextBlock" xlink:label="us-gaap_LesseeOperatingLeasesTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeasesTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Operating Leases [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeasesTextBlock" xlink:to="us-gaap_LesseeOperatingLeasesTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceived" xlink:label="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceived" xlink:type="locator"/>
    <link:label xlink:label="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceived-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceived</link:label>
    <link:label xlink:label="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceived-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Contingent Liability, Repayment of State and Local Grant Funds Received</link:label>
    <link:label xlink:label="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceived-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of liability recognized arising from contingent for repayment of state and local grant funds received.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceived" xlink:to="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceived-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccountsPayableCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts payable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableCurrent" xlink:to="us-gaap_AccountsPayableCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="us-gaap_RevolvingCreditFacilityMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RevolvingCreditFacilityMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revolving Credit Facility [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevolvingCreditFacilityMember" xlink:to="us-gaap_RevolvingCreditFacilityMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Options outstanding, number of shares (in shares)</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Options outstanding, number of shares (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CreditFacilityAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Credit Facility [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from sale of property and equipment</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CreditFacilityDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Credit Facility [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_CreditFacilityDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAccruedLiabilitiesCurrent" xlink:to="us-gaap_OtherAccruedLiabilitiesCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TrademarksMember" xlink:label="us-gaap_TrademarksMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TrademarksMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Trademarks [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TrademarksMember" xlink:to="us-gaap_TrademarksMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PolicyTextBlockAbstract" xlink:label="us-gaap_PolicyTextBlockAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PolicyTextBlockAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PolicyTextBlockAbstract</link:label>
    <link:label xlink:label="us-gaap_PolicyTextBlockAbstract-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounting Policies</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PolicyTextBlockAbstract" xlink:to="us-gaap_PolicyTextBlockAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_CityOfRochesterAndStateOfNewYorkMember" xlink:label="intt_CityOfRochesterAndStateOfNewYorkMember" xlink:type="locator"/>
    <link:label xlink:label="intt_CityOfRochesterAndStateOfNewYorkMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">City of Rochester and State of New York [Member]</link:label>
    <link:label xlink:label="intt_CityOfRochesterAndStateOfNewYorkMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information related to city of Rochester and state of New York.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_CityOfRochesterAndStateOfNewYorkMember" xlink:to="intt_CityOfRochesterAndStateOfNewYorkMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyAccrualClassifiedCurrent" xlink:label="us-gaap_ProductWarrantyAccrualClassifiedCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ProductWarrantyAccrualClassifiedCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrued warranty</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductWarrantyAccrualClassifiedCurrent" xlink:to="us-gaap_ProductWarrantyAccrualClassifiedCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="us-gaap_TradeNamesMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TradeNamesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Trade Names [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TradeNamesMember" xlink:to="us-gaap_TradeNamesMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccruedSalesCommissionCurrent" xlink:label="us-gaap_AccruedSalesCommissionCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccruedSalesCommissionCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AccruedSalesCommissionCurrent</link:label>
    <link:label xlink:label="us-gaap_AccruedSalesCommissionCurrent-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accrued sales commission</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedSalesCommissionCurrent" xlink:to="us-gaap_AccruedSalesCommissionCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssued1" xlink:label="us-gaap_StockIssued1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssued1-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Issuance of unvested shares of restricted stock</link:label>
    <link:label xlink:label="us-gaap_StockIssued1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockIssued1</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssued1" xlink:to="us-gaap_StockIssued1-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="us-gaap_AccruedProfessionalFeesCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccruedProfessionalFeesCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrued professional fees</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedProfessionalFeesCurrent" xlink:to="us-gaap_AccruedProfessionalFeesCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Indefinite-lived Intangible Assets [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceivedPolicyPolicyTextBlock" xlink:label="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceivedPolicyPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceivedPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Contingent Liability, Repayment of State and Local Grant Funds Received, Policy [Policy Text Block]</link:label>
    <link:label xlink:label="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceivedPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Disclosure of accounting policy for contingent liability for repayment of state and local grant funds received.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceivedPolicyPolicyTextBlock" xlink:to="intt_ContingentLiabilityRepaymentOfStateAndLocalGrantFundsReceivedPolicyPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Indefinite-lived Intangible Assets, Major Class Name [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Capital expenditures</link:label>
    <link:label xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PaymentsToAcquirePropertyPlantAndEquipment</link:label>
    <link:label xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Purchase of property and equipment</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:label="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Unvested shares of restricted stock and employee stock options (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:to="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_NoncashInvestingAndFinancingItemsAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod</link:label>
    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock" xlink:label="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock" xlink:to="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_DiscountedCashFlowsDiscountRate" xlink:label="intt_DiscountedCashFlowsDiscountRate" xlink:type="locator"/>
    <link:label xlink:label="intt_DiscountedCashFlowsDiscountRate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_DiscountedCashFlowsDiscountRate</link:label>
    <link:label xlink:label="intt_DiscountedCashFlowsDiscountRate-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Discounted Cash Flows, Discount Rate</link:label>
    <link:label xlink:label="intt_DiscountedCashFlowsDiscountRate-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Discount rate used by discounted cash flows.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_DiscountedCashFlowsDiscountRate" xlink:to="intt_DiscountedCashFlowsDiscountRate-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage</link:label>
    <link:label xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationAwardTrancheThreeMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement, Tranche Three [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:to="us-gaap_ShareBasedCompensationAwardTrancheThreeMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="us-gaap_LiabilitiesCurrentAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LiabilitiesCurrentAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Current liabilities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_LiabilitiesCurrentAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VestingAxis" xlink:label="us-gaap_VestingAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_VestingAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Vesting [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VestingAxis" xlink:to="us-gaap_VestingAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VestingDomain" xlink:label="us-gaap_VestingDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_VestingDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Vesting [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VestingDomain" xlink:to="us-gaap_VestingDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PatentedTechnologyMember" xlink:label="us-gaap_PatentedTechnologyMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PatentedTechnologyMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Patented Technology [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PatentedTechnologyMember" xlink:to="us-gaap_PatentedTechnologyMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationAwardTrancheOneMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement, Tranche One [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:to="us-gaap_ShareBasedCompensationAwardTrancheOneMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationAwardTrancheTwoMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement, Tranche Two [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:to="us-gaap_ShareBasedCompensationAwardTrancheTwoMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SupplementalCashFlowInformationAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash payments for:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_Assets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_Assets</link:label>
    <link:label xlink:label="us-gaap_Assets-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total assets</link:label>
    <link:label xlink:label="us-gaap_Assets-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Identifiable Assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_OperatingLeaseImpairmentLoss-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Impairment of right of use assets</link:label>
    <link:label xlink:label="us-gaap_OperatingLeaseImpairmentLoss-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Impairment of ROU asset</link:label>
    <link:label xlink:label="us-gaap_OperatingLeaseImpairmentLoss-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Lease, Impairment Loss</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseImpairmentLoss" xlink:to="us-gaap_OperatingLeaseImpairmentLoss-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_RestructuringImpairmentAndOtherActivitiesDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restructuring, Impairment, and Other Activities Disclosure [Text Block]</link:label>
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    <link:label xlink:label="us-gaap_PlanNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Plan Name [Domain]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentAbstract-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_GoodwillIntangibleAndLongLivedAssetsPolicyTextBlock" xlink:label="intt_GoodwillIntangibleAndLongLivedAssetsPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="intt_GoodwillIntangibleAndLongLivedAssetsPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Goodwill Intangible And Long Lived Assets [Policy Text Block]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_GoodwillIntangibleAndLongLivedAssetsPolicyTextBlock" xlink:to="intt_GoodwillIntangibleAndLongLivedAssetsPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:type="locator"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="us-gaap_CustomerRelationshipsMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CustomerRelationshipsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Customer Relationships [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CustomerRelationshipsMember" xlink:to="us-gaap_CustomerRelationshipsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LegalMattersAndContingenciesTextBlock" xlink:label="us-gaap_LegalMattersAndContingenciesTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LegalMattersAndContingenciesTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Legal Matters and Contingencies [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LegalMattersAndContingenciesTextBlock" xlink:to="us-gaap_LegalMattersAndContingenciesTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount</link:label>
    <link:label xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement, Amount Capitalized</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ComputerSoftwareIntangibleAssetMember" xlink:label="us-gaap_ComputerSoftwareIntangibleAssetMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ComputerSoftwareIntangibleAssetMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Computer Software, Intangible Asset [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComputerSoftwareIntangibleAssetMember" xlink:to="us-gaap_ComputerSoftwareIntangibleAssetMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets by Major Class [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-Lived Intangible Assets, Major Class Name [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:to="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseOfRestrictedInvestments" xlink:label="us-gaap_IncreaseDecreaseOfRestrictedInvestments" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseOfRestrictedInvestments-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseOfRestrictedInvestments</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseOfRestrictedInvestments-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Restricted certificates of deposit</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseOfRestrictedInvestments" xlink:to="us-gaap_IncreaseDecreaseOfRestrictedInvestments-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Award Type [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_IncomeTaxReconciliationIncomeTaxReconciliationGlobalIntangibleLowTaxedIncome" xlink:label="intt_IncomeTaxReconciliationIncomeTaxReconciliationGlobalIntangibleLowTaxedIncome" xlink:type="locator"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_IncomeTaxReconciliationIncomeTaxReconciliationGlobalIntangibleLowTaxedIncome" xlink:to="intt_IncomeTaxReconciliationIncomeTaxReconciliationGlobalIntangibleLowTaxedIncome-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AwardTypeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Award Type [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_AwardTypeAxis-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_NetIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Net earnings (loss)</link:label>
    <link:label xlink:label="us-gaap_NetIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net earnings (loss)</link:label>
    <link:label xlink:label="us-gaap_NetIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net earnings (loss)</link:label>
    <link:label xlink:label="us-gaap_NetIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net earnings (loss)</link:label>
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    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-lived, Accumulated Amortization</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Carrying Amount</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Balance</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Balance</link:label>
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    <link:label xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Intangible assets, net</link:label>
    <link:label xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net Carrying Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finite-lived, Gross Carrying Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsGross" xlink:to="us-gaap_FiniteLivedIntangibleAssetsGross-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="us-gaap_RestrictedStockMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RestrictedStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restricted Stock [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockMember" xlink:to="us-gaap_RestrictedStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="us-gaap_EmployeeStockOptionMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EmployeeStockOptionMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement, Option [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeStockOptionMember" xlink:to="us-gaap_EmployeeStockOptionMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ScheduleOfIntangibleAssetsTableTextBlock" xlink:label="intt_ScheduleOfIntangibleAssetsTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="intt_ScheduleOfIntangibleAssetsTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule Of Intangible Assets [Table Text Block]</link:label>
    <link:label xlink:label="intt_ScheduleOfIntangibleAssetsTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The tabular disclosure of the intangible assets.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ScheduleOfIntangibleAssetsTableTextBlock" xlink:to="intt_ScheduleOfIntangibleAssetsTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_AmbrellMember" xlink:label="intt_AmbrellMember" xlink:type="locator"/>
    <link:label xlink:label="intt_AmbrellMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Ambrell [Member]</link:label>
    <link:label xlink:label="intt_AmbrellMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the acquisition of Ambrell.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_AmbrellMember" xlink:to="intt_AmbrellMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Net Carrying Amount</link:label>
    <link:label xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill</link:label>
    <link:label xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Indefinite-lived, Gross Carrying Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment</link:label>
    <link:label xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Less: accumulated depreciation</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PropertyPlantAndEquipmentNet</link:label>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentNet-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net property and equipment</link:label>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentNet-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property and Equipment</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_Goodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Goodwill</link:label>
    <link:label xlink:label="us-gaap_Goodwill-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Goodwill, Ending Balance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Goodwill" xlink:to="us-gaap_Goodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="us-gaap_PropertyPlantAndEquipmentGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PropertyPlantAndEquipmentGross</link:label>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentGross-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Gross property and equipment</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentGross" xlink:to="us-gaap_PropertyPlantAndEquipmentGross-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MachineryAndEquipmentGross" xlink:label="us-gaap_MachineryAndEquipmentGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_MachineryAndEquipmentGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Machinery and equipment</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MachineryAndEquipmentGross" xlink:to="us-gaap_MachineryAndEquipmentGross-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LeaseholdImprovementsGross" xlink:label="us-gaap_LeaseholdImprovementsGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LeaseholdImprovementsGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Leasehold improvements</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseholdImprovementsGross" xlink:to="us-gaap_LeaseholdImprovementsGross-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_IncreaseDecreaseInOperatingLeaseLiabilities" xlink:label="intt_IncreaseDecreaseInOperatingLeaseLiabilities" xlink:type="locator"/>
    <link:label xlink:label="intt_IncreaseDecreaseInOperatingLeaseLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating lease liabilities</link:label>
    <link:label xlink:label="intt_IncreaseDecreaseInOperatingLeaseLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of increase (decrease) in operating lease liabilities.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_IncreaseDecreaseInOperatingLeaseLiabilities" xlink:to="intt_IncreaseDecreaseInOperatingLeaseLiabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_EMSMember" xlink:label="intt_EMSMember" xlink:type="locator"/>
    <link:label xlink:label="intt_EMSMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EMS [Member]</link:label>
    <link:label xlink:label="intt_EMSMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the information pertaining to inTEST Electromechanical Semiconductor Products (EMS).</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_EMSMember" xlink:to="intt_EMSMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_IncreaseDecreaseInAccruedProfessionalFees" xlink:label="intt_IncreaseDecreaseInAccruedProfessionalFees" xlink:type="locator"/>
    <link:label xlink:label="intt_IncreaseDecreaseInAccruedProfessionalFees-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Accrued professional fees</link:label>
    <link:label xlink:label="intt_IncreaseDecreaseInAccruedProfessionalFees-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_IncreaseDecreaseInAccruedProfessionalFees</link:label>
    <link:label xlink:label="intt_IncreaseDecreaseInAccruedProfessionalFees-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The amount of increase (decrease) in accrued professional fees.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_IncreaseDecreaseInAccruedProfessionalFees" xlink:to="intt_IncreaseDecreaseInAccruedProfessionalFees-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_DeferredTaxAssetsAcquisitionCosts" xlink:label="intt_DeferredTaxAssetsAcquisitionCosts" xlink:type="locator"/>
    <link:label xlink:label="intt_DeferredTaxAssetsAcquisitionCosts-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Acquisition costs</link:label>
    <link:label xlink:label="intt_DeferredTaxAssetsAcquisitionCosts-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_DeferredTaxAssetsAcquisitionCosts</link:label>
    <link:label xlink:label="intt_DeferredTaxAssetsAcquisitionCosts-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount before allocation of valuation allowances of deferred tax asset attributable to deductible acquisition costs.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_DeferredTaxAssetsAcquisitionCosts" xlink:to="intt_DeferredTaxAssetsAcquisitionCosts-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_LeaseForFacilityInMansfieldMassachusettsMember" xlink:label="intt_LeaseForFacilityInMansfieldMassachusettsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_LeaseForFacilityInMansfieldMassachusettsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease for Facility in Mansfield, Massachusetts [Member]</link:label>
    <link:label xlink:label="intt_LeaseForFacilityInMansfieldMassachusettsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to a lease.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_LeaseForFacilityInMansfieldMassachusettsMember" xlink:to="intt_LeaseForFacilityInMansfieldMassachusettsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_EmployeesMember" xlink:label="intt_EmployeesMember" xlink:type="locator"/>
    <link:label xlink:label="intt_EmployeesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Employees [Member]</link:label>
    <link:label xlink:label="intt_EmployeesMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to employees.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_EmployeesMember" xlink:to="intt_EmployeesMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">CASH FLOWS FROM INVESTING ACTIVITIES</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_OperatingLeaseRemainingLeaseTerm" xlink:label="intt_OperatingLeaseRemainingLeaseTerm" xlink:type="locator"/>
    <link:label xlink:label="intt_OperatingLeaseRemainingLeaseTerm-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Range of remaining lease terms (in years) (Year)</link:label>
    <link:label xlink:label="intt_OperatingLeaseRemainingLeaseTerm-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The remaining lease term of operating leases.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_OperatingLeaseRemainingLeaseTerm" xlink:to="intt_OperatingLeaseRemainingLeaseTerm-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ShareBasedCompensationAwardTrancheFourMember" xlink:label="intt_ShareBasedCompensationAwardTrancheFourMember" xlink:type="locator"/>
    <link:label xlink:label="intt_ShareBasedCompensationAwardTrancheFourMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Compensation Award, Tranche Four [Member]</link:label>
    <link:label xlink:label="intt_ShareBasedCompensationAwardTrancheFourMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fourth portion of share-based compensation award differentiated by a particular vesting feature, including, but not limited to, performance measure or service period.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ShareBasedCompensationAwardTrancheFourMember" xlink:to="intt_ShareBasedCompensationAwardTrancheFourMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable" xlink:label="us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Domestic and foreign income taxes payable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable" xlink:to="us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LetterOfCreditMember" xlink:label="us-gaap_LetterOfCreditMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LetterOfCreditMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Letter of Credit [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LetterOfCreditMember" xlink:to="us-gaap_LetterOfCreditMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accrued wages and benefits</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Earnings (loss) before income tax expense (benefit)</link:label>
    <link:label xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments</link:label>
    <link:label xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:label xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earnings (loss) before income tax expense (benefit)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Income tax expense (benefit)</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Income tax expense (benefit)</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Income tax expense (benefit)</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Income tax expense (benefit)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_TheAmbrellPlanMember" xlink:label="intt_TheAmbrellPlanMember" xlink:type="locator"/>
    <link:label xlink:label="intt_TheAmbrellPlanMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">The Ambrell Plan [Member]</link:label>
    <link:label xlink:label="intt_TheAmbrellPlanMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Related to the Ambrell defined contribution retirement plan.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_TheAmbrellPlanMember" xlink:to="intt_TheAmbrellPlanMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_OtherRestructuringActionsMember" xlink:label="intt_OtherRestructuringActionsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_OtherRestructuringActionsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Restructuring Actions [Member]</link:label>
    <link:label xlink:label="intt_OtherRestructuringActionsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents other restructuring actions.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_OtherRestructuringActionsMember" xlink:to="intt_OtherRestructuringActionsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SeveranceAndOtherOneTimeTerminationBenefits" xlink:label="intt_SeveranceAndOtherOneTimeTerminationBenefits" xlink:type="locator"/>
    <link:label xlink:label="intt_SeveranceAndOtherOneTimeTerminationBenefits-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Severance and other one-time termination benefits</link:label>
    <link:label xlink:label="intt_SeveranceAndOtherOneTimeTerminationBenefits-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents severance and other one-time termination benefits.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SeveranceAndOtherOneTimeTerminationBenefits" xlink:to="intt_SeveranceAndOtherOneTimeTerminationBenefits-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInAccountsPayable</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounts payable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingExpenses-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_OperatingExpenses</link:label>
    <link:label xlink:label="us-gaap_OperatingExpenses-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total operating expenses</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_OperatingExpenses-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsNoncurrent" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsNoncurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RestrictedCashAndCashEquivalentsNoncurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restricted certificates of deposit</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsNoncurrent" xlink:to="us-gaap_RestrictedCashAndCashEquivalentsNoncurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount" xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount</link:label>
    <link:label xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan, Employer Discretionary Contribution Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount" xlink:to="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GeneralAndAdministrativeExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">General and administrative expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeneralAndAdministrativeExpense" xlink:to="us-gaap_GeneralAndAdministrativeExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount" xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount</link:label>
    <link:label xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount" xlink:to="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_RestructuringAndOtherCharges" xlink:label="intt_RestructuringAndOtherCharges" xlink:type="locator"/>
    <link:label xlink:label="intt_RestructuringAndOtherCharges-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Restructuring and other charges</link:label>
    <link:label xlink:label="intt_RestructuringAndOtherCharges-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_RestructuringAndOtherCharges</link:label>
    <link:label xlink:label="intt_RestructuringAndOtherCharges-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of expenses associated with exit or disposal activities pursuant to an authorized plan and other charges. Excludes expenses related to a discontinued operation or an asset retirement obligation.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_RestructuringAndOtherCharges" xlink:to="intt_RestructuringAndOtherCharges-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent</link:label>
    <link:label xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:to="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent</link:label>
    <link:label xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:to="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch</link:label>
    <link:label xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan, Employer Matching Contribution, Percent of Match</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch" xlink:to="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash and cash equivalents</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xlink:label="us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInOtherCurrentLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInOtherCurrentLiabilities</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInOtherCurrentLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other current liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xlink:to="us-gaap_IncreaseDecreaseInOtherCurrentLiabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllowanceForCreditLossMember" xlink:label="us-gaap_AllowanceForCreditLossMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AllowanceForCreditLossMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">SEC Schedule, 12-09, Allowance, Credit Loss [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForCreditLossMember" xlink:to="us-gaap_AllowanceForCreditLossMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_DefinedContributionPlanMaximumAnnualEmployerMatchingContributionPerEmplyeeAmount" xlink:label="intt_DefinedContributionPlanMaximumAnnualEmployerMatchingContributionPerEmplyeeAmount" xlink:type="locator"/>
    <link:label xlink:label="intt_DefinedContributionPlanMaximumAnnualEmployerMatchingContributionPerEmplyeeAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_DefinedContributionPlanMaximumAnnualEmployerMatchingContributionPerEmplyeeAmount</link:label>
    <link:label xlink:label="intt_DefinedContributionPlanMaximumAnnualEmployerMatchingContributionPerEmplyeeAmount-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan Maximum Annual Employer Matching Contribution Per Emplyee Amount</link:label>
    <link:label xlink:label="intt_DefinedContributionPlanMaximumAnnualEmployerMatchingContributionPerEmplyeeAmount-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Maximum dollar amount of employer's annual matching contribution to a defined contribution plan</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_DefinedContributionPlanMaximumAnnualEmployerMatchingContributionPerEmplyeeAmount" xlink:to="intt_DefinedContributionPlanMaximumAnnualEmployerMatchingContributionPerEmplyeeAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AllocatedShareBasedCompensationExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AllocatedShareBasedCompensationExpense</link:label>
    <link:label xlink:label="us-gaap_AllocatedShareBasedCompensationExpense-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Allocation of Share-based Compensation Expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllocatedShareBasedCompensationExpense" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_AssetMember" xlink:label="intt_AssetMember" xlink:type="locator"/>
    <link:label xlink:label="intt_AssetMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Asset [Member]</link:label>
    <link:label xlink:label="intt_AssetMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The information pertaining to a financial statement line item.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_AssetMember" xlink:to="intt_AssetMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag" xlink:type="locator"/>
    <link:label xlink:label="dei_AmendmentFlag-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amendment Flag</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ComprehensiveIncomeNetOfTax-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ComprehensiveIncomeNetOfTax</link:label>
    <link:label xlink:label="us-gaap_ComprehensiveIncomeNetOfTax-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Comprehensive earnings (loss)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">New Accounting Pronouncements, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:label="us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PriorPeriodReclassificationAdjustmentDescription-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Reclassification, Comparability Adjustment [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:to="us-gaap_PriorPeriodReclassificationAdjustmentDescription-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_GainLossOnSaleOfPropertyPlantEquipment</link:label>
    <link:label xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Loss on disposal of property and equipment</link:label>
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    <link:label xlink:label="dei_CurrentFiscalYearEndDate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Current Fiscal Year End Date</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:to="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent-label" xlink:type="arc"/>
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    <link:label xlink:label="dei_DocumentFiscalPeriodFocus-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Fiscal Period Focus</link:label>
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    <link:label xlink:label="us-gaap_OperatingLeaseCost-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating lease cost</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseCost" xlink:to="us-gaap_OperatingLeaseCost-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus" xlink:type="locator"/>
    <link:label xlink:label="dei_DocumentFiscalYearFocus-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Fiscal Year Focus</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalYearFocus" xlink:to="dei_DocumentFiscalYearFocus-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShortTermLeaseCost" xlink:label="us-gaap_ShortTermLeaseCost" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShortTermLeaseCost-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Short-term lease cost</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermLeaseCost" xlink:to="us-gaap_ShortTermLeaseCost-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCostTableTextBlock" xlink:to="us-gaap_LeaseCostTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate" xlink:type="locator"/>
    <link:label xlink:label="dei_DocumentPeriodEndDate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Period End Date</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentPeriodEndDate" xlink:to="dei_DocumentPeriodEndDate-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseExpirationDate1" xlink:to="us-gaap_LeaseExpirationDate1-label" xlink:type="arc"/>
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    <link:label xlink:label="dei_DocumentType-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Type</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentType" xlink:to="dei_DocumentType-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness" xlink:type="locator"/>
    <link:label xlink:label="dei_EntitySmallBusiness-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Small Business</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntitySmallBusiness" xlink:to="dei_EntitySmallBusiness-label" xlink:type="arc"/>
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    <link:label xlink:label="dei_EntityShellCompany-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Shell Company</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityShellCompany" xlink:to="dei_EntityShellCompany-label" xlink:type="arc"/>
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    <link:label xlink:label="dei_DocumentInformationLineItems-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Information [Line Items]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentInformationLineItems-label" xlink:type="arc"/>
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    <link:label xlink:label="dei_DocumentInformationTable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Information [Table]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentInformationTable" xlink:to="dei_DocumentInformationTable-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AreaOfRealEstateProperty" xlink:label="us-gaap_AreaOfRealEstateProperty" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AreaOfRealEstateProperty-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AreaOfRealEstateProperty</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AreaOfRealEstateProperty" xlink:to="us-gaap_AreaOfRealEstateProperty-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityPublicFloat" xlink:label="dei_EntityPublicFloat" xlink:type="locator"/>
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    <link:label xlink:label="dei_EntityFilerCategory-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Filer Category</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherRestructuringCosts" xlink:to="us-gaap_OtherRestructuringCosts-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_DebtInstrumentAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis-label" xlink:type="arc"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="us-gaap_DebtInstrumentNameDomain-label" xlink:type="arc"/>
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    <link:label xlink:label="dei_EntityVoluntaryFilers-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Voluntary Filers</link:label>
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    <link:label xlink:label="us-gaap_LondonInterbankOfferedRateLIBORMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">London Interbank Offered Rate (LIBOR) [Member]</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="us-gaap_VariableRateDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_VariableRateDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Rate [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableRateDomain" xlink:to="us-gaap_VariableRateDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="us-gaap_VariableRateAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_VariableRateAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Rate [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableRateAxis" xlink:to="us-gaap_VariableRateAxis-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_ConcentrationRiskPercentage1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ConcentrationRiskPercentage1</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInAccountsReceivable</link:label>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Trade accounts receivable</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amortization of deferred compensation related to stock-based awards</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_QuarterlyFinancialInformationTextBlock" xlink:label="us-gaap_QuarterlyFinancialInformationTextBlock" xlink:type="locator"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_QuarterlyFinancialInformationTextBlock" xlink:to="us-gaap_QuarterlyFinancialInformationTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement of Comprehensive Income [Abstract]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityCentralIndexKey-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Central Index Key</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCentralIndexKey" xlink:to="dei_EntityCentralIndexKey-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:label="us-gaap_DepreciationAndAmortization" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DepreciationAndAmortization-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Depreciation/amortization</link:label>
    <link:label xlink:label="us-gaap_DepreciationAndAmortization-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DepreciationAndAmortization</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationAndAmortization" xlink:to="us-gaap_DepreciationAndAmortization-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityRegistrantName-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityRegistrantName" xlink:to="dei_EntityRegistrantName-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityDomain" xlink:label="dei_EntityDomain" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityDomain" xlink:to="dei_EntityDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="us-gaap_CustomerConcentrationRiskMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CustomerConcentrationRiskMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Customer Concentration Risk [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CustomerConcentrationRiskMember" xlink:to="us-gaap_CustomerConcentrationRiskMember-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_LegalEntityAxis" xlink:label="dei_LegalEntityAxis" xlink:type="locator"/>
    <link:label xlink:label="dei_LegalEntityAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Legal Entity [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LegalEntityAxis" xlink:to="dei_LegalEntityAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AmortizationOfIntangibleAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AmortizationOfIntangibleAssets</link:label>
    <link:label xlink:label="us-gaap_AmortizationOfIntangibleAssets-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Amortization</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfIntangibleAssets" xlink:to="us-gaap_AmortizationOfIntangibleAssets-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="us-gaap_ConcentrationRiskByTypeAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConcentrationRiskByTypeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk Type [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByTypeAxis" xlink:to="us-gaap_ConcentrationRiskByTypeAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="us-gaap_ConcentrationRiskTypeDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConcentrationRiskTypeDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk Type [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskTypeDomain" xlink:to="us-gaap_ConcentrationRiskTypeDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AllowanceForDoubtfulAccountsReceivable</link:label>
    <link:label xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Balance</link:label>
    <link:label xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Balance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockValue" xlink:label="us-gaap_TreasuryStockValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TreasuryStockValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_TreasuryStockValue</link:label>
    <link:label xlink:label="us-gaap_TreasuryStockValue-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Treasury stock, at cost; 33,077 shares</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockValue" xlink:to="us-gaap_TreasuryStockValue-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding" xlink:type="locator"/>
    <link:label xlink:label="dei_EntityCommonStockSharesOutstanding-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Common Stock, Shares Outstanding (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCommonStockSharesOutstanding" xlink:to="dei_EntityCommonStockSharesOutstanding-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue" xlink:label="us-gaap_StockRepurchasedAndRetiredDuringPeriodValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockRepurchasedAndRetiredDuringPeriodValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockRepurchasedAndRetiredDuringPeriodValue</link:label>
    <link:label xlink:label="us-gaap_StockRepurchasedAndRetiredDuringPeriodValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock Repurchased and Retired During Period, Value</link:label>
    <link:label xlink:label="us-gaap_StockRepurchasedAndRetiredDuringPeriodValue-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Repurchase and retirement of common stock</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockRepurchasedAndRetiredDuringPeriodValue" xlink:to="us-gaap_StockRepurchasedAndRetiredDuringPeriodValue-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares" xlink:label="us-gaap_StockRepurchasedAndRetiredDuringPeriodShares" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockRepurchasedAndRetiredDuringPeriodShares-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockRepurchasedAndRetiredDuringPeriodShares</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SalesRevenueNetMember" xlink:label="us-gaap_SalesRevenueNetMember" xlink:type="locator"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SalesRevenueNetMember" xlink:to="us-gaap_SalesRevenueNetMember-label" xlink:type="arc"/>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherNoncurrentAssets" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInOtherNoncurrentAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncreaseDecreaseInOtherNoncurrentAssets</link:label>
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    <link:loc xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol" xlink:type="locator"/>
    <link:label xlink:label="dei_TradingSymbol-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Trading Symbol</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_TradingSymbol" xlink:to="dei_TradingSymbol-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk Benchmark [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk Benchmark [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NatureOfOperations" xlink:label="us-gaap_NatureOfOperations" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NatureOfOperations-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Nature of Operations [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NatureOfOperations" xlink:to="us-gaap_NatureOfOperations-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Exercised, number of shares (in shares)</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TableTextBlock" xlink:label="us-gaap_TableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_TableTextBlock</link:label>
    <link:label xlink:label="us-gaap_TableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Notes Tables</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TableTextBlock" xlink:to="us-gaap_TableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Issuance of unvested shares of restricted stock (in shares)</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Forfeiture of unvested shares of restricted stock (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity</link:label>
    <link:label xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Maximum Borrowing Capacity</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity</link:label>
    <link:label xlink:label="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Current Borrowing Capacity</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Issuance of unvested shares of restricted stock</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross</link:label>
    <link:label xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Issuance of unvested shares of restricted stock</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="us-gaap_ProvisionForDoubtfulAccounts" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ProvisionForDoubtfulAccounts-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ProvisionForDoubtfulAccounts</link:label>
    <link:label xlink:label="us-gaap_ProvisionForDoubtfulAccounts-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accounts Receivable, Credit Loss Expense (Reversal)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProvisionForDoubtfulAccounts" xlink:to="us-gaap_ProvisionForDoubtfulAccounts-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Granted, number of shares (in shares)</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Canceled, number of shares (in shares)</link:label>
    <link:label xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityInitiationDate1" xlink:label="us-gaap_LineOfCreditFacilityInitiationDate1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LineOfCreditFacilityInitiationDate1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit, Issue Date</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInitiationDate1" xlink:to="us-gaap_LineOfCreditFacilityInitiationDate1-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityExpirationDate1" xlink:label="us-gaap_LineOfCreditFacilityExpirationDate1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LineOfCreditFacilityExpirationDate1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit, Expiration Date</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityExpirationDate1" xlink:to="us-gaap_LineOfCreditFacilityExpirationDate1-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:label="us-gaap_LineOfCreditFacilityLenderDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LineOfCreditFacilityLenderDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Lender [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityLenderDomain" xlink:to="us-gaap_LineOfCreditFacilityLenderDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryRawMaterialsNetOfReserves" xlink:label="us-gaap_InventoryRawMaterialsNetOfReserves" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryRawMaterialsNetOfReserves-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Raw materials</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryRawMaterialsNetOfReserves" xlink:to="us-gaap_InventoryRawMaterialsNetOfReserves-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityAxis" xlink:label="us-gaap_LineOfCreditFacilityAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LineOfCreditFacilityAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lender Name [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityAxis" xlink:to="us-gaap_LineOfCreditFacilityAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SellingExpense" xlink:label="us-gaap_SellingExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SellingExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Selling expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingExpense" xlink:to="us-gaap_SellingExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LiabilitiesAndStockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LiabilitiesAndStockholdersEquity</link:label>
    <link:label xlink:label="us-gaap_LiabilitiesAndStockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total liabilities and stockholders' equity</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finished goods</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:to="us-gaap_InventoryFinishedGoodsNetOfReserves-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryWorkInProcessNetOfReserves" xlink:label="us-gaap_InventoryWorkInProcessNetOfReserves" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryWorkInProcessNetOfReserves-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Work in process</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryWorkInProcessNetOfReserves" xlink:to="us-gaap_InventoryWorkInProcessNetOfReserves-label" xlink:type="arc"/>
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="country_US" xlink:type="locator"/>
    <link:label xlink:label="country_US-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">UNITED STATES</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="country_US" xlink:to="country_US-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_EMSSegmentRestructuringAndFacilityConsolidationMember" xlink:label="intt_EMSSegmentRestructuringAndFacilityConsolidationMember" xlink:type="locator"/>
    <link:label xlink:label="intt_EMSSegmentRestructuringAndFacilityConsolidationMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EMS Segment Restructuring and Facility Consolidation [Member]</link:label>
    <link:label xlink:label="intt_EMSSegmentRestructuringAndFacilityConsolidationMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information related to the facility consolidation and EMS segment restructuring.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_EMSSegmentRestructuringAndFacilityConsolidationMember" xlink:to="intt_EMSSegmentRestructuringAndFacilityConsolidationMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SharebasedPaymentArrangementReversalOfExpense" xlink:label="intt_SharebasedPaymentArrangementReversalOfExpense" xlink:type="locator"/>
    <link:label xlink:label="intt_SharebasedPaymentArrangementReversalOfExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_SharebasedPaymentArrangementReversalOfExpense</link:label>
    <link:label xlink:label="intt_SharebasedPaymentArrangementReversalOfExpense-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement, Reversal of Expense</link:label>
    <link:label xlink:label="intt_SharebasedPaymentArrangementReversalOfExpense-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of expense for award under share-based payment arrangement that has been reversed as result of forfeiture of awards.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SharebasedPaymentArrangementReversalOfExpense" xlink:to="intt_SharebasedPaymentArrangementReversalOfExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Retained earnings</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ResearchAndDevelopmentExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Engineering and product development expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpense" xlink:to="us-gaap_ResearchAndDevelopmentExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accumulated other comprehensive earnings</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ExecutiveManagementChangesMember" xlink:label="intt_ExecutiveManagementChangesMember" xlink:type="locator"/>
    <link:label xlink:label="intt_ExecutiveManagementChangesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Executive Management Changes [Member]</link:label>
    <link:label xlink:label="intt_ExecutiveManagementChangesMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Restructuring related to the resignation of executive management.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ExecutiveManagementChangesMember" xlink:to="intt_ExecutiveManagementChangesMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_LeaseAgreementAmbrellsNetherlandsFacilityMember" xlink:label="intt_LeaseAgreementAmbrellsNetherlandsFacilityMember" xlink:type="locator"/>
    <link:label xlink:label="intt_LeaseAgreementAmbrellsNetherlandsFacilityMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease Agreement, Ambrell&#8217;s Netherlands Facility [Member]</link:label>
    <link:label xlink:label="intt_LeaseAgreementAmbrellsNetherlandsFacilityMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents lease agreement, Ambrell&#8217;s Netherlands facility.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_LeaseAgreementAmbrellsNetherlandsFacilityMember" xlink:to="intt_LeaseAgreementAmbrellsNetherlandsFacilityMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtDisclosureTextBlock" xlink:label="us-gaap_DebtDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DebtDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtDisclosureTextBlock" xlink:to="us-gaap_DebtDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SupplementalCashFlowInfomationLesseeTableTextBlock" xlink:label="intt_SupplementalCashFlowInfomationLesseeTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="intt_SupplementalCashFlowInfomationLesseeTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Supplemental Cash Flow Infomation, Lessee [Table Text Block]</link:label>
    <link:label xlink:label="intt_SupplementalCashFlowInfomationLesseeTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tabular disclosure of lessee's supplemental cash flow information.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SupplementalCashFlowInfomationLesseeTableTextBlock" xlink:to="intt_SupplementalCashFlowInfomationLesseeTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Changes in assets and liabilities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_LeaseAgreementEmsFacilityInMtLaurelNewJerseyMember" xlink:label="intt_LeaseAgreementEmsFacilityInMtLaurelNewJerseyMember" xlink:type="locator"/>
    <link:label xlink:label="intt_LeaseAgreementEmsFacilityInMtLaurelNewJerseyMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease Agreement, EMS Facility in Mt. Laurel, New Jersey [Member]</link:label>
    <link:label xlink:label="intt_LeaseAgreementEmsFacilityInMtLaurelNewJerseyMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents lease agreement, EMS facility in Mt. Laurel, New Jersey.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_LeaseAgreementEmsFacilityInMtLaurelNewJerseyMember" xlink:to="intt_LeaseAgreementEmsFacilityInMtLaurelNewJerseyMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisclosureTextBlockAbstract" xlink:label="us-gaap_DisclosureTextBlockAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DisclosureTextBlockAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DisclosureTextBlockAbstract</link:label>
    <link:label xlink:label="us-gaap_DisclosureTextBlockAbstract-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Notes to Financial Statements</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureTextBlockAbstract" xlink:to="us-gaap_DisclosureTextBlockAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryDisclosureTextBlock" xlink:label="us-gaap_InventoryDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Inventory Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureTextBlock" xlink:to="us-gaap_InventoryDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating lease liabilities, net of current portion</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:label="us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfInventoryCurrentTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Inventory, Current [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:to="us-gaap_ScheduleOfInventoryCurrentTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedFairValue" xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedFairValue" xlink:type="locator"/>
    <link:label xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedFairValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedFairValue</link:label>
    <link:label xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedFairValue-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Granted, Fair Value</link:label>
    <link:label xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedFairValue-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fair value of awards other than options granted during the period.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedFairValue" xlink:to="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedFairValue-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_RestrictedStockVestingInThreeYearsMember" xlink:label="intt_RestrictedStockVestingInThreeYearsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_RestrictedStockVestingInThreeYearsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restricted Stock Vesting in Three Years [Member]</link:label>
    <link:label xlink:label="intt_RestrictedStockVestingInThreeYearsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information related to the restricted stock awards vesting in three years.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_RestrictedStockVestingInThreeYearsMember" xlink:to="intt_RestrictedStockVestingInThreeYearsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseLiability-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiability" xlink:to="us-gaap_OperatingLeaseLiability-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseLiabilityCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Current portion of operating lease liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityCurrent" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Retirement Benefits [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:to="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IntangibleAssetsGrossExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IntangibleAssetsGrossExcludingGoodwill</link:label>
    <link:label xlink:label="us-gaap_IntangibleAssetsGrossExcludingGoodwill-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Intangible Assets, Gross Carrying Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:to="us-gaap_IntangibleAssetsGrossExcludingGoodwill-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_RestrictedStockVestingInFourYearsMember" xlink:label="intt_RestrictedStockVestingInFourYearsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_RestrictedStockVestingInFourYearsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restricted Stock Vesting in Four Years [Member]</link:label>
    <link:label xlink:label="intt_RestrictedStockVestingInFourYearsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information related to the restricted stock awards vesting in four years.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_RestrictedStockVestingInFourYearsMember" xlink:to="intt_RestrictedStockVestingInFourYearsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseRightOfUseAsset-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Right of use assets, net</link:label>
    <link:label xlink:label="us-gaap_OperatingLeaseRightOfUseAsset-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Lease, Right-of-Use Asset</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total lease payments</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Less imputed interest</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred income tax benefit</link:label>
    <link:label xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2023</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2024</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2025</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Thereafter</link:label>
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    <link:label xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Measurement, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:to="us-gaap_FairValueMeasurementPolicyPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2022</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2023</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2024</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2021</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2025</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo</link:label>
    <link:label xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2022</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:label="us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:to="us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRestructuring" xlink:label="us-gaap_PaymentsForRestructuring" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PaymentsForRestructuring-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PaymentsForRestructuring</link:label>
    <link:label xlink:label="us-gaap_PaymentsForRestructuring-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Cash payments</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForRestructuring" xlink:to="us-gaap_PaymentsForRestructuring-label" xlink:type="arc"/>
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    <link:label xlink:label="us-gaap_SubsequentEventsPolicyPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Events, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsPolicyPolicyTextBlock" xlink:to="us-gaap_SubsequentEventsPolicyPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths</link:label>
    <link:label xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2021</link:label>
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    <link:label xlink:label="us-gaap_RestructuringCosts-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_RestructuringCosts</link:label>
    <link:label xlink:label="us-gaap_RestructuringCosts-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="us-gaap_ValuationAllowancesAndReservesDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ValuationAllowancesAndReservesDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain]</link:label>
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    <link:label xlink:label="us-gaap_WarrantyReservesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">SEC Schedule, 12-09, Reserve, Warranty [Member]</link:label>
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    <link:label xlink:label="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Foreign Currency Transactions and Translations Policy [Policy Text Block]</link:label>
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    <link:label xlink:label="us-gaap_LesseeOperatingLeaseRenewalTerm-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Lessee, Operating Lease, Renewal Term (Month)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseRenewalTerm" xlink:to="us-gaap_LesseeOperatingLeaseRenewalTerm-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Research and Development Expense, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:to="us-gaap_ResearchAndDevelopmentExpensePolicy-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_DeferredTaxAssetsOperatingLeases" xlink:label="intt_DeferredTaxAssetsOperatingLeases" xlink:type="locator"/>
    <link:label xlink:label="intt_DeferredTaxAssetsOperatingLeases-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Operating lease liabilities</link:label>
    <link:label xlink:label="intt_DeferredTaxAssetsOperatingLeases-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_DeferredTaxAssetsOperatingLeases</link:label>
    <link:label xlink:label="intt_DeferredTaxAssetsOperatingLeases-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from operating leases.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_DeferredTaxAssetsOperatingLeases" xlink:to="intt_DeferredTaxAssetsOperatingLeases-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Depreciation" xlink:label="us-gaap_Depreciation" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_Depreciation-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_Depreciation</link:label>
    <link:label xlink:label="us-gaap_Depreciation-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Depreciation, Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Depreciation" xlink:to="us-gaap_Depreciation-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DepreciationDepletionAndAmortization-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Depreciation and amortization</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationDepletionAndAmortization" xlink:to="us-gaap_DepreciationDepletionAndAmortization-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_DeferredTaxLiabilitiesRightOfUseAssets" xlink:label="intt_DeferredTaxLiabilitiesRightOfUseAssets" xlink:type="locator"/>
    <link:label xlink:label="intt_DeferredTaxLiabilitiesRightOfUseAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_DeferredTaxLiabilitiesRightOfUseAssets</link:label>
    <link:label xlink:label="intt_DeferredTaxLiabilitiesRightOfUseAssets-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Right of use assets</link:label>
    <link:label xlink:label="intt_DeferredTaxLiabilitiesRightOfUseAssets-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of deferred tax liability attributable to taxable temporary differences from right-of-use assets.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_DeferredTaxLiabilitiesRightOfUseAssets" xlink:to="intt_DeferredTaxLiabilitiesRightOfUseAssets-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageLowerRange" xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageLowerRange" xlink:type="locator"/>
    <link:label xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageLowerRange-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageLowerRange</link:label>
    <link:label xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageLowerRange-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement By Share-based Payment Award, Award Vesting Rights Percentage Lower Range</link:label>
    <link:label xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageLowerRange-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Lower range limit of percentage of vesting of award under share-based payment arrangement.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageLowerRange" xlink:to="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageLowerRange-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageUpperRange" xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageUpperRange" xlink:type="locator"/>
    <link:label xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageUpperRange-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageUpperRange</link:label>
    <link:label xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageUpperRange-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement By Share-based Payment Award, Award Vesting Rights Percentage Upper Range</link:label>
    <link:label xlink:label="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageUpperRange-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Upper range limit of percentage of vesting of award under share-based payment arrangement.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageUpperRange" xlink:to="intt_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentageUpperRange-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AssetsCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_AssetsCurrent</link:label>
    <link:label xlink:label="us-gaap_AssetsCurrent-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total current assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Payment Arrangement [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:to="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockShares" xlink:label="us-gaap_TreasuryStockShares" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TreasuryStockShares-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Treasury stock, shares (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockShares" xlink:to="us-gaap_TreasuryStockShares-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common stock, $0.01 par value; 20,000,000 shares authorized; 10,562,200 and 10,413,982 shares issued, respectively</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Adjustments to reconcile net earnings (loss) to net cash provided by (used in) operating activities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockSharesAuthorized-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common stock, shares authorized (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common stock, shares issued (in shares)</link:label>
    <link:label xlink:label="us-gaap_CommonStockSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Balance (in shares)</link:label>
    <link:label xlink:label="us-gaap_CommonStockSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Balance (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesIssued" xlink:to="us-gaap_CommonStockSharesIssued-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockParOrStatedValuePerShare-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common stock, par value (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount</link:label>
    <link:label xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" xlink:to="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsValuationAllowance</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Valuation allowance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_DeferredTaxAssetsValuationAllowance-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="srt_RangeMember" xlink:type="locator"/>
    <link:label xlink:label="srt_RangeMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statistical Measurement [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeMember" xlink:to="srt_RangeMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember" xlink:type="locator"/>
    <link:label xlink:label="srt_MaximumMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Maximum [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember" xlink:type="locator"/>
    <link:label xlink:label="srt_MinimumMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Minimum [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MinimumMember" xlink:to="srt_MinimumMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_ProductOrServiceAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Product and Service [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductOrServiceAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="us-gaap_DeferredTaxAssetsNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsNet</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsNet-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Deferred tax assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsNet" xlink:to="us-gaap_DeferredTaxAssetsNet-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="srt_ProductsAndServicesDomain" xlink:type="locator"/>
    <link:label xlink:label="srt_ProductsAndServicesDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Product and Service [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductsAndServicesDomain" xlink:to="srt_ProductsAndServicesDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_RangeAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statistical Measurement [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeAxis" xlink:to="srt_RangeAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PreferredStockValue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred stock, $0.01 par value; 5,000,000 shares authorized; no shares issued or outstanding</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockValue" xlink:to="us-gaap_PreferredStockValue-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PreferredStockSharesIssued-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred stock, shares issued (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesIssued" xlink:to="us-gaap_PreferredStockSharesIssued-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxesPaid" xlink:label="us-gaap_IncomeTaxesPaid" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxesPaid-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Domestic and foreign income taxes</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxesPaid" xlink:to="us-gaap_IncomeTaxesPaid-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOther" xlink:label="us-gaap_DeferredTaxAssetsOther" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsOther-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsOther-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsOther</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOther" xlink:to="us-gaap_DeferredTaxAssetsOther-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="srt_StatementGeographicalAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_StatementGeographicalAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Geographical [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_StatementGeographicalAxis" xlink:to="srt_StatementGeographicalAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="srt_SegmentGeographicalDomain" xlink:type="locator"/>
    <link:label xlink:label="srt_SegmentGeographicalDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Geographical [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_SegmentGeographicalDomain" xlink:to="srt_SegmentGeographicalDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="us-gaap_DeferredTaxAssetsGross" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsGross-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsGross</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsGross-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsGross" xlink:to="us-gaap_DeferredTaxAssetsGross-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PreferredStockSharesAuthorized-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred stock, shares authorized (in shares)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesAuthorized" xlink:to="us-gaap_PreferredStockSharesAuthorized-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilities" xlink:label="us-gaap_DeferredIncomeTaxLiabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredIncomeTaxLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredIncomeTaxLiabilities</link:label>
    <link:label xlink:label="us-gaap_DeferredIncomeTaxLiabilities-label" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xml:lang="en-US">Deferred tax liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxLiabilities" xlink:to="us-gaap_DeferredIncomeTaxLiabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryNet" xlink:label="us-gaap_InventoryNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Inventories</link:label>
    <link:label xlink:label="us-gaap_InventoryNet-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total inventories</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryNet" xlink:to="us-gaap_InventoryNet-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Preferred stock par value (in dollars per share)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Net revenues</link:label>
    <link:label xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net revenues</link:label>
    <link:label xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Net revenues</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_ForeignCurrencyTransactionGainLossBeforeTax</link:label>
    <link:label xlink:label="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Foreign Currency Transaction Gain (Loss), before Tax, Total</link:label>
    <link:label xlink:label="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Foreign exchange loss</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:to="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MajorCustomersAxis" xlink:label="srt_MajorCustomersAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_MajorCustomersAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Customer [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MajorCustomersAxis" xlink:to="srt_MajorCustomersAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsInventory" xlink:label="us-gaap_DeferredTaxAssetsInventory" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsInventory-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Inventories</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsInventory-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsInventory</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsInventory" xlink:to="us-gaap_DeferredTaxAssetsInventory-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_NameOfMajorCustomerDomain" xlink:label="srt_NameOfMajorCustomerDomain" xlink:type="locator"/>
    <link:label xlink:label="srt_NameOfMajorCustomerDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Customer [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="srt_NameOfMajorCustomerDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ScheduleOfChangesInAllowanceForDoubtfulAccountsReceivableTableTextBlock" xlink:label="intt_ScheduleOfChangesInAllowanceForDoubtfulAccountsReceivableTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="intt_ScheduleOfChangesInAllowanceForDoubtfulAccountsReceivableTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Changes in Allowance for Doubtful Accounts Receivable [Table Text Block]</link:label>
    <link:label xlink:label="intt_ScheduleOfChangesInAllowanceForDoubtfulAccountsReceivableTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tabular disclosure of the changes in the allowance for doubtful accounts receivable.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ScheduleOfChangesInAllowanceForDoubtfulAccountsReceivableTableTextBlock" xlink:to="intt_ScheduleOfChangesInAllowanceForDoubtfulAccountsReceivableTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_OEMAndIntegratorsMember" xlink:label="intt_OEMAndIntegratorsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_OEMAndIntegratorsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">OEM and Integrators [Member]</link:label>
    <link:label xlink:label="intt_OEMAndIntegratorsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Customers who are original equipment manufacturers and/or integrators.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_OEMAndIntegratorsMember" xlink:to="intt_OEMAndIntegratorsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherInventoryMaterialsSuppliesAndMerchandiseUnderConsignment" xlink:label="us-gaap_OtherInventoryMaterialsSuppliesAndMerchandiseUnderConsignment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OtherInventoryMaterialsSuppliesAndMerchandiseUnderConsignment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Inventory consigned to others</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherInventoryMaterialsSuppliesAndMerchandiseUnderConsignment" xlink:to="us-gaap_OtherInventoryMaterialsSuppliesAndMerchandiseUnderConsignment-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_EndUserMember" xlink:label="intt_EndUserMember" xlink:type="locator"/>
    <link:label xlink:label="intt_EndUserMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">End User [Member]</link:label>
    <link:label xlink:label="intt_EndUserMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Customers who are the end user of the company's products.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_EndUserMember" xlink:to="intt_EndUserMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SemiconductorMarketMember" xlink:label="intt_SemiconductorMarketMember" xlink:type="locator"/>
    <link:label xlink:label="intt_SemiconductorMarketMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Semiconductor Market [Member]</link:label>
    <link:label xlink:label="intt_SemiconductorMarketMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The semiconductor market into which the reporting entity sells products.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SemiconductorMarketMember" xlink:to="intt_SemiconductorMarketMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ServiceAndOtherProductsMember" xlink:label="intt_ServiceAndOtherProductsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_ServiceAndOtherProductsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Service and Other Products [Member]</link:label>
    <link:label xlink:label="intt_ServiceAndOtherProductsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information about services and other products sold by the reporting entity.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ServiceAndOtherProductsMember" xlink:to="intt_ServiceAndOtherProductsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SemiconductorProductionTestProductsMember" xlink:label="intt_SemiconductorProductionTestProductsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_SemiconductorProductionTestProductsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Semiconductor Production Test Products [Member]</link:label>
    <link:label xlink:label="intt_SemiconductorProductionTestProductsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information about semiconductor production test products sold by the reporting entity.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SemiconductorProductionTestProductsMember" xlink:to="intt_SemiconductorProductionTestProductsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PropertyPlantAndEquipmentUsefulLife</link:label>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment, Useful Life (Year)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_TelecommunicationsMarketMember" xlink:label="intt_TelecommunicationsMarketMember" xlink:type="locator"/>
    <link:label xlink:label="intt_TelecommunicationsMarketMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Telecommunications Market [Member]</link:label>
    <link:label xlink:label="intt_TelecommunicationsMarketMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The telecommunications market into which the reporting entity sells products.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_TelecommunicationsMarketMember" xlink:to="intt_TelecommunicationsMarketMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_IndustrialMarketMember" xlink:label="intt_IndustrialMarketMember" xlink:type="locator"/>
    <link:label xlink:label="intt_IndustrialMarketMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Industrial Market [Member]</link:label>
    <link:label xlink:label="intt_IndustrialMarketMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The industrial market into which the reporting entity sells products.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_IndustrialMarketMember" xlink:to="intt_IndustrialMarketMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">CASH FLOWS FROM OPERATING ACTIVITIES</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Accrued warranty</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_The401KPlanMember" xlink:label="intt_The401KPlanMember" xlink:type="locator"/>
    <link:label xlink:label="intt_The401KPlanMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">401(k) Plan [Member]</link:label>
    <link:label xlink:label="intt_The401KPlanMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">A 401(k) plan offered by the reporting entity to eligible employees.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_The401KPlanMember" xlink:to="intt_The401KPlanMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Allowance for doubtful accounts</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRecognitionPolicyTextBlock" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenue [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRecognitionPolicyTextBlock" xlink:to="us-gaap_RevenueRecognitionPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StatementLineItems-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statement [Line Items]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementLineItems-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Allowance for doubtful accounts</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Accrued vacation pay and stock-based compensation</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="us-gaap_NumberOfOperatingSegments" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NumberOfOperatingSegments-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NumberOfOperatingSegments</link:label>
    <link:label xlink:label="us-gaap_NumberOfOperatingSegments-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of Operating Segments</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfOperatingSegments" xlink:to="us-gaap_NumberOfOperatingSegments-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccountsReceivableNetCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Trade accounts receivable, net of allowance for doubtful accounts of $212 and $211, respectively</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNetCurrent" xlink:to="us-gaap_AccountsReceivableNetCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:label="us-gaap_NumberOfReportableSegments" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NumberOfReportableSegments-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NumberOfReportableSegments</link:label>
    <link:label xlink:label="us-gaap_NumberOfReportableSegments-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of Reportable Segments</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfReportableSegments" xlink:to="us-gaap_NumberOfReportableSegments-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AdditionalPaidInCapital-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Additional paid-in capital</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapital" xlink:to="us-gaap_AdditionalPaidInCapital-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">AOCI Attributable to Parent [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockholdersEquityAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stockholders' equity:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OtherNonoperatingIncomeExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other income (loss)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_SegmentReportingDisclosureTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segment Reporting Disclosure [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingDisclosureTextBlock" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Tax credit carryforwards</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:to="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Net operating loss (state and foreign)</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxAssetsOperatingLossCarryforwards</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ProceedsFromSaleOfMachineryAndEquipmentNetOfGain" xlink:label="intt_ProceedsFromSaleOfMachineryAndEquipmentNetOfGain" xlink:type="locator"/>
    <link:label xlink:label="intt_ProceedsFromSaleOfMachineryAndEquipmentNetOfGain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Proceeds from sale of demonstration equipment, net of gain</link:label>
    <link:label xlink:label="intt_ProceedsFromSaleOfMachineryAndEquipmentNetOfGain-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Proceeds from sale of machinery and equipment net of gain.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ProceedsFromSaleOfMachineryAndEquipmentNetOfGain" xlink:to="intt_ProceedsFromSaleOfMachineryAndEquipmentNetOfGain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="us-gaap_AssetsCurrentAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AssetsCurrentAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Current assets:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrentAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ThermonicsMember" xlink:label="intt_ThermonicsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_ThermonicsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Thermonics [Member]</link:label>
    <link:label xlink:label="intt_ThermonicsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information about Thermonics.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ThermonicsMember" xlink:to="intt_ThermonicsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SigmaMember" xlink:label="intt_SigmaMember" xlink:type="locator"/>
    <link:label xlink:label="intt_SigmaMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sigma [Member]</link:label>
    <link:label xlink:label="intt_SigmaMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information about Sigma.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SigmaMember" xlink:to="intt_SigmaMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations</link:label>
    <link:label xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Cash and cash equivalents at beginning of period</link:label>
    <link:label xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Cash and cash equivalents at end of period</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryPolicyTextBlock" xlink:label="us-gaap_InventoryPolicyTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryPolicyTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Inventory, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryPolicyTextBlock" xlink:to="us-gaap_InventoryPolicyTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:label="us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Effects of exchange rates on cash</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:to="us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect</link:label>
    <link:label xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash provided by (used in) all activities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsNetAbstract" xlink:label="us-gaap_DeferredTaxAssetsNetAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxAssetsNetAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred tax assets:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsNetAbstract" xlink:to="us-gaap_DeferredTaxAssetsNetAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_TexasInstrumentsIncorporatedMember" xlink:label="intt_TexasInstrumentsIncorporatedMember" xlink:type="locator"/>
    <link:label xlink:label="intt_TexasInstrumentsIncorporatedMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Texas Instruments Incorporated [Member]</link:label>
    <link:label xlink:label="intt_TexasInstrumentsIncorporatedMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Texas instruments incorporated member.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_TexasInstrumentsIncorporatedMember" xlink:to="intt_TexasInstrumentsIncorporatedMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NetCashProvidedByUsedInFinancingActivities</link:label>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash used in financing activities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_Liabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_Liabilities</link:label>
    <link:label xlink:label="us-gaap_Liabilities-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommitmentsAndContingencies-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commitments and Contingencies (Note 12)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingencies" xlink:to="us-gaap_CommitmentsAndContingencies-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ScheduleOfOutstandingLettersOfCreditTableTextBlock" xlink:label="intt_ScheduleOfOutstandingLettersOfCreditTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="intt_ScheduleOfOutstandingLettersOfCreditTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule Of Outstanding Letters Of Credit [Table Text Block]</link:label>
    <link:label xlink:label="intt_ScheduleOfOutstandingLettersOfCreditTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Schedule of outstanding letters of credit table text block.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ScheduleOfOutstandingLettersOfCreditTableTextBlock" xlink:to="intt_ScheduleOfOutstandingLettersOfCreditTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_MtLaurelMember" xlink:label="intt_MtLaurelMember" xlink:type="locator"/>
    <link:label xlink:label="intt_MtLaurelMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Mt Laurel [Member]</link:label>
    <link:label xlink:label="intt_MtLaurelMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information about Mt laurel.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_MtLaurelMember" xlink:to="intt_MtLaurelMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Operating income (loss)</link:label>
    <link:label xlink:label="us-gaap_OperatingIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_OperatingIncomeLoss</link:label>
    <link:label xlink:label="us-gaap_OperatingIncomeLoss-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Operating income (loss)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NetCashProvidedByUsedInOperatingActivities</link:label>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash provided by (used in) operating activities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_MansfieldMember" xlink:label="intt_MansfieldMember" xlink:type="locator"/>
    <link:label xlink:label="intt_MansfieldMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Mansfield [Member]</link:label>
    <link:label xlink:label="intt_MansfieldMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information about Mansfield.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_MansfieldMember" xlink:to="intt_MansfieldMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_NetCashProvidedByUsedInInvestingActivities</link:label>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash used in investing activities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxLiabilities" xlink:label="us-gaap_DeferredTaxLiabilities" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxLiabilities-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxLiabilities</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxLiabilities-label" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xml:lang="en-US">Net deferred tax liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilities" xlink:to="us-gaap_DeferredTaxLiabilities-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Prepaid expenses and other current assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Net intangible assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:to="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfRevenue" xlink:label="us-gaap_CostOfRevenue" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CostOfRevenue-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cost of revenues</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostOfRevenue" xlink:to="us-gaap_CostOfRevenue-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_IncomeTaxReconciliationEffectsOfNetOperatingLossAndTaxCreditCarryforwards" xlink:label="intt_IncomeTaxReconciliationEffectsOfNetOperatingLossAndTaxCreditCarryforwards" xlink:type="locator"/>
    <link:label xlink:label="intt_IncomeTaxReconciliationEffectsOfNetOperatingLossAndTaxCreditCarryforwards-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_IncomeTaxReconciliationEffectsOfNetOperatingLossAndTaxCreditCarryforwards</link:label>
    <link:label xlink:label="intt_IncomeTaxReconciliationEffectsOfNetOperatingLossAndTaxCreditCarryforwards-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">NOL carryforwards utilized</link:label>
    <link:label xlink:label="intt_IncomeTaxReconciliationEffectsOfNetOperatingLossAndTaxCreditCarryforwards-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Income tax reconciliation effects of net operating loss and tax credit carryforwards.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_IncomeTaxReconciliationEffectsOfNetOperatingLossAndTaxCreditCarryforwards" xlink:to="intt_IncomeTaxReconciliationEffectsOfNetOperatingLossAndTaxCreditCarryforwards-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GrossProfit" xlink:label="us-gaap_GrossProfit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_GrossProfit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_GrossProfit</link:label>
    <link:label xlink:label="us-gaap_GrossProfit-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Gross margin</link:label>
    <link:label xlink:label="us-gaap_GrossProfit-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Gross margin</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GrossProfit" xlink:to="us-gaap_GrossProfit-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_DefinedContributionPlanEmployerMatchingContributionVestingPeriod" xlink:label="intt_DefinedContributionPlanEmployerMatchingContributionVestingPeriod" xlink:type="locator"/>
    <link:label xlink:label="intt_DefinedContributionPlanEmployerMatchingContributionVestingPeriod-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_DefinedContributionPlanEmployerMatchingContributionVestingPeriod</link:label>
    <link:label xlink:label="intt_DefinedContributionPlanEmployerMatchingContributionVestingPeriod-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Defined Contribution Plan Employer Matching Contribution Vesting Period (Year)</link:label>
    <link:label xlink:label="intt_DefinedContributionPlanEmployerMatchingContributionVestingPeriod-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Defined contribution plan employer matching contribution vesting period.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_DefinedContributionPlanEmployerMatchingContributionVestingPeriod" xlink:to="intt_DefinedContributionPlanEmployerMatchingContributionVestingPeriod-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CounterpartyNameAxis" xlink:label="srt_CounterpartyNameAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_CounterpartyNameAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Counterparty Name [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_CounterpartyNameAxis" xlink:to="srt_CounterpartyNameAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain" xlink:type="locator"/>
    <link:label xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Counterparty Name [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain" xlink:to="srt_RepurchaseAgreementCounterpartyNameDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:label="us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredIncomeTaxLiabilitiesNet-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred tax liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:to="us-gaap_DeferredIncomeTaxLiabilitiesNet-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="srt_ConsolidationItemsDomain" xlink:type="locator"/>
    <link:label xlink:label="srt_ConsolidationItemsDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidation Items [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ConsolidationItemsDomain" xlink:to="srt_ConsolidationItemsDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryWriteDown" xlink:label="us-gaap_InventoryWriteDown" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_InventoryWriteDown-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Provision for excess and obsolete inventory</link:label>
    <link:label xlink:label="us-gaap_InventoryWriteDown-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Inventory Write-down</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryWriteDown" xlink:to="us-gaap_InventoryWriteDown-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ThermalTestingProductsMember" xlink:label="intt_ThermalTestingProductsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_ThermalTestingProductsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Thermal Testing Products [Member]</link:label>
    <link:label xlink:label="intt_ThermalTestingProductsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information about Thermal products sold by the reporting entity.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ThermalTestingProductsMember" xlink:to="intt_ThermalTestingProductsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="srt_ConsolidationItemsAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_ConsolidationItemsAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidation Items [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ConsolidationItemsAxis" xlink:to="srt_ConsolidationItemsAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ValuationAllowancesAndReservesTableTextBlock" xlink:label="intt_ValuationAllowancesAndReservesTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="intt_ValuationAllowancesAndReservesTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Valuation Allowances and Reserves [Table Text Block]</link:label>
    <link:label xlink:label="intt_ValuationAllowancesAndReservesTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tabular disclosure of a schedule of allowance and reserve accounts where the valuation and qualifying accounts are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ValuationAllowancesAndReservesTableTextBlock" xlink:to="intt_ValuationAllowancesAndReservesTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment</link:label>
    <link:label xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Depreciation of property and equipment</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:to="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_MTMember" xlink:label="intt_MTMember" xlink:type="locator"/>
    <link:label xlink:label="intt_MTMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">M&amp;T [Member]</link:label>
    <link:label xlink:label="intt_MTMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information about M&amp;T.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_MTMember" xlink:to="intt_MTMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="us-gaap_LettersOfCreditOutstandingAmount" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_LettersOfCreditOutstandingAmount-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Letters of Credit Amount Outstanding</link:label>
    <link:label xlink:label="us-gaap_LettersOfCreditOutstandingAmount-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Letters of Credit Outstanding, Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LettersOfCreditOutstandingAmount" xlink:to="us-gaap_LettersOfCreditOutstandingAmount-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxLiabilitiesNetAbstract" xlink:label="us-gaap_DeferredTaxLiabilitiesNetAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredTaxLiabilitiesNetAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Deferred tax liabilities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesNetAbstract" xlink:to="us-gaap_DeferredTaxLiabilitiesNetAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_PresidentMember" xlink:label="srt_PresidentMember" xlink:type="locator"/>
    <link:label xlink:label="srt_PresidentMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">President [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_PresidentMember" xlink:to="srt_PresidentMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_LeaseAgreementEMSFacilityInFremontCaliforniaMember" xlink:label="intt_LeaseAgreementEMSFacilityInFremontCaliforniaMember" xlink:type="locator"/>
    <link:label xlink:label="intt_LeaseAgreementEMSFacilityInFremontCaliforniaMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease Agreement, EMS Facility in Fremont, California [Member]</link:label>
    <link:label xlink:label="intt_LeaseAgreementEMSFacilityInFremontCaliforniaMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents lease agreement, EMS facility in Fremont, California.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_LeaseAgreementEMSFacilityInFremontCaliforniaMember" xlink:to="intt_LeaseAgreementEMSFacilityInFremontCaliforniaMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_LeaseAgreementAmbrellsUKMember" xlink:label="intt_LeaseAgreementAmbrellsUKMember" xlink:type="locator"/>
    <link:label xlink:label="intt_LeaseAgreementAmbrellsUKMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lease Agreement, Ambrell&#8217;s U.K [Member]</link:label>
    <link:label xlink:label="intt_LeaseAgreementAmbrellsUKMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents lease agreement, Ambrell&#8217;s U.K.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_LeaseAgreementAmbrellsUKMember" xlink:to="intt_LeaseAgreementAmbrellsUKMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_PaymentsForRepurchaseOfCommonStock</link:label>
    <link:label xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock-label" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Repurchases of common stock</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:to="us-gaap_PaymentsForRepurchaseOfCommonStock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="srt_ScenarioUnspecifiedDomain" xlink:type="locator"/>
    <link:label xlink:label="srt_ScenarioUnspecifiedDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Scenario [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScenarioUnspecifiedDomain" xlink:to="srt_ScenarioUnspecifiedDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioForecastMember" xlink:label="srt_ScenarioForecastMember" xlink:type="locator"/>
    <link:label xlink:label="srt_ScenarioForecastMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Forecast [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScenarioForecastMember" xlink:to="srt_ScenarioForecastMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RetainedEarningsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Retained Earnings [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsMember" xlink:to="us-gaap_RetainedEarningsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:type="locator"/>
    <link:label xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Title of Individual [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:to="srt_TitleOfIndividualWithRelationshipToEntityDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_CurrentStateAndLocalTaxExpenseBenefit</link:label>
    <link:label xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Domestic &#8211; state</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:to="us-gaap_CurrentStateAndLocalTaxExpenseBenefit-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_TitleOfIndividualAxis" xlink:label="srt_TitleOfIndividualAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_TitleOfIndividualAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Title of Individual [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_TitleOfIndividualAxis" xlink:to="srt_TitleOfIndividualAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit</link:label>
    <link:label xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Domestic &#8211; state</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockMember" xlink:label="us-gaap_TreasuryStockMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TreasuryStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Treasury Stock [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockMember" xlink:to="us-gaap_TreasuryStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementScenarioAxis" xlink:label="srt_StatementScenarioAxis" xlink:type="locator"/>
    <link:label xlink:label="srt_StatementScenarioAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Scenario [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_StatementScenarioAxis" xlink:to="srt_StatementScenarioAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_CurrentForeignTaxExpenseBenefit</link:label>
    <link:label xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Foreign</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentForeignTaxExpenseBenefit" xlink:to="us-gaap_CurrentForeignTaxExpenseBenefit-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredForeignIncomeTaxExpenseBenefit</link:label>
    <link:label xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Foreign</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredForeignIncomeTaxExpenseBenefit-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_AdditionalPaidInCapitalMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Additional Paid-in Capital [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalMember" xlink:to="us-gaap_AdditionalPaidInCapitalMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_CurrentFederalTaxExpenseBenefit</link:label>
    <link:label xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Domestic &#8211; Federal</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentFederalTaxExpenseBenefit" xlink:to="us-gaap_CurrentFederalTaxExpenseBenefit-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CommonStockMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1" xlink:label="us-gaap_StockRepurchaseProgramAuthorizedAmount1" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockRepurchaseProgramAuthorizedAmount1-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockRepurchaseProgramAuthorizedAmount1</link:label>
    <link:label xlink:label="us-gaap_StockRepurchaseProgramAuthorizedAmount1-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Stock Repurchase Program, Authorized Amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockRepurchaseProgramAuthorizedAmount1" xlink:to="us-gaap_StockRepurchaseProgramAuthorizedAmount1-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_DeferredFederalIncomeTaxExpenseBenefit</link:label>
    <link:label xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Domestic &#8211; Federal</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredFederalIncomeTaxExpenseBenefit-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_IncreaseDecreaseInAccruedSalesCommission" xlink:label="intt_IncreaseDecreaseInAccruedSalesCommission" xlink:type="locator"/>
    <link:label xlink:label="intt_IncreaseDecreaseInAccruedSalesCommission-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_IncreaseDecreaseInAccruedSalesCommission</link:label>
    <link:label xlink:label="intt_IncreaseDecreaseInAccruedSalesCommission-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accrued sales commission</link:label>
    <link:label xlink:label="intt_IncreaseDecreaseInAccruedSalesCommission-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The increase (decrease) during the reporting period in accrued sales commission.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_IncreaseDecreaseInAccruedSalesCommission" xlink:to="intt_IncreaseDecreaseInAccruedSalesCommission-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_IncreaseInOperatingLeaseLiabilitiesAndRightofuseAssetsNonCash" xlink:label="intt_IncreaseInOperatingLeaseLiabilitiesAndRightofuseAssetsNonCash" xlink:type="locator"/>
    <link:label xlink:label="intt_IncreaseInOperatingLeaseLiabilitiesAndRightofuseAssetsNonCash-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Non-cash increases in operating lease liabilites and ROU assets</link:label>
    <link:label xlink:label="intt_IncreaseInOperatingLeaseLiabilitiesAndRightofuseAssetsNonCash-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Increase in Operating Lease Liabilities and Right-of-Use Assets, Non-cash</link:label>
    <link:label xlink:label="intt_IncreaseInOperatingLeaseLiabilitiesAndRightofuseAssetsNonCash-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the non-cash increase in operating lease liabilities and right-of-use assets.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_IncreaseInOperatingLeaseLiabilitiesAndRightofuseAssetsNonCash" xlink:to="intt_IncreaseInOperatingLeaseLiabilitiesAndRightofuseAssetsNonCash-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_OperatingLeaseIncreaseInArea" xlink:label="intt_OperatingLeaseIncreaseInArea" xlink:type="locator"/>
    <link:label xlink:label="intt_OperatingLeaseIncreaseInArea-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_OperatingLeaseIncreaseInArea</link:label>
    <link:label xlink:label="intt_OperatingLeaseIncreaseInArea-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Lease, Increase in Area (Square Foot)</link:label>
    <link:label xlink:label="intt_OperatingLeaseIncreaseInArea-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the amount of increase in the area of an operating lease during the period.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_OperatingLeaseIncreaseInArea" xlink:to="intt_OperatingLeaseIncreaseInArea-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_MansfieldMassachusettsMember" xlink:label="intt_MansfieldMassachusettsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_MansfieldMassachusettsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Mansfield, Massachusetts [Member]</link:label>
    <link:label xlink:label="intt_MansfieldMassachusettsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information pertaining to Mansfield, Massachusetts.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_MansfieldMassachusettsMember" xlink:to="intt_MansfieldMassachusettsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StatementEquityComponentsAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Components [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_StatementEquityComponentsAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EquityComponentDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity Component [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_EquityComponentDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_CurrentIncomeTaxExpenseBenefit</link:label>
    <link:label xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:to="us-gaap_CurrentIncomeTaxExpenseBenefit-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign-label" xlink:type="arc"/>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:to="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Deferred Tax Assets and Liabilities [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanAxis" xlink:label="us-gaap_RestructuringPlanAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RestructuringPlanAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restructuring Plan [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestructuringPlanAxis" xlink:to="us-gaap_RestructuringPlanAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanDomain" xlink:label="us-gaap_RestructuringPlanDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RestructuringPlanDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restructuring Plan [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestructuringPlanDomain" xlink:to="us-gaap_RestructuringPlanDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeRelocationMember" xlink:label="us-gaap_EmployeeRelocationMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EmployeeRelocationMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Employee Relocation [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeRelocationMember" xlink:to="us-gaap_EmployeeRelocationMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_IncomeTaxReconciliationDeemedDividendFromForeignSubsidiaries" xlink:label="intt_IncomeTaxReconciliationDeemedDividendFromForeignSubsidiaries" xlink:type="locator"/>
    <link:label xlink:label="intt_IncomeTaxReconciliationDeemedDividendFromForeignSubsidiaries-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_IncomeTaxReconciliationDeemedDividendFromForeignSubsidiaries</link:label>
    <link:label xlink:label="intt_IncomeTaxReconciliationDeemedDividendFromForeignSubsidiaries-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Dividend from foreign subsidiaries</link:label>
    <link:label xlink:label="intt_IncomeTaxReconciliationDeemedDividendFromForeignSubsidiaries-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to a deemed dividend from foreign subsidiaries.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_IncomeTaxReconciliationDeemedDividendFromForeignSubsidiaries" xlink:to="intt_IncomeTaxReconciliationDeemedDividendFromForeignSubsidiaries-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="us-gaap_TypeOfRestructuringDomain" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_TypeOfRestructuringDomain-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Type of Restructuring [Domain]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfRestructuringDomain" xlink:to="us-gaap_TypeOfRestructuringDomain-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FacilityClosingMember" xlink:label="us-gaap_FacilityClosingMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_FacilityClosingMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Facility Closing [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FacilityClosingMember" xlink:to="us-gaap_FacilityClosingMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock" xlink:label="us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restructuring and Related Costs [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock" xlink:to="us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="us-gaap_RestructuringCostAndReserveAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_RestructuringCostAndReserveAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Restructuring Type [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestructuringCostAndReserveAxis" xlink:to="us-gaap_RestructuringCostAndReserveAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ThermalProcessMember" xlink:label="intt_ThermalProcessMember" xlink:type="locator"/>
    <link:label xlink:label="intt_ThermalProcessMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Thermal Process [Member]</link:label>
    <link:label xlink:label="intt_ThermalProcessMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents thermal process.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ThermalProcessMember" xlink:to="intt_ThermalProcessMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_StockPlan2014Member" xlink:label="intt_StockPlan2014Member" xlink:type="locator"/>
    <link:label xlink:label="intt_StockPlan2014Member-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Plan 2014 [Member]</link:label>
    <link:label xlink:label="intt_StockPlan2014Member-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the 2014 Stock Plan.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_StockPlan2014Member" xlink:to="intt_StockPlan2014Member-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">CASH FLOWS FROM FINANCING ACTIVITIES</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationOtherReconcilingItems" xlink:label="us-gaap_IncomeTaxReconciliationOtherReconcilingItems" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationOtherReconcilingItems-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationOtherReconcilingItems</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationOtherReconcilingItems-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationOtherReconcilingItems" xlink:to="us-gaap_IncomeTaxReconciliationOtherReconcilingItems-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate</link:label>
    <link:label xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="us-gaap_OtherLiabilitiesNoncurrent" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OtherLiabilitiesNoncurrent-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesNoncurrent" xlink:to="us-gaap_OtherLiabilitiesNoncurrent-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Changes in valuation allowance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_DefenseAerospaceMember" xlink:label="intt_DefenseAerospaceMember" xlink:type="locator"/>
    <link:label xlink:label="intt_DefenseAerospaceMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Defense/ Aerospace [Member]</link:label>
    <link:label xlink:label="intt_DefenseAerospaceMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents defense/ aerospace.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_DefenseAerospaceMember" xlink:to="intt_DefenseAerospaceMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_StockRepurchasePlanTextBlock" xlink:label="intt_StockRepurchasePlanTextBlock" xlink:type="locator"/>
    <link:label xlink:label="intt_StockRepurchasePlanTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Stock Repurchase Plan [Text Block]</link:label>
    <link:label xlink:label="intt_StockRepurchasePlanTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The entire disclosure for stock repurchase plan.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_StockRepurchasePlanTextBlock" xlink:to="intt_StockRepurchasePlanTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ProceedsFromPaycheckProtectionProgramUnderCaresAct" xlink:label="intt_ProceedsFromPaycheckProtectionProgramUnderCaresAct" xlink:type="locator"/>
    <link:label xlink:label="intt_ProceedsFromPaycheckProtectionProgramUnderCaresAct-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_ProceedsFromPaycheckProtectionProgramUnderCaresAct</link:label>
    <link:label xlink:label="intt_ProceedsFromPaycheckProtectionProgramUnderCaresAct-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from Paycheck Protection Program Under CARES Act</link:label>
    <link:label xlink:label="intt_ProceedsFromPaycheckProtectionProgramUnderCaresAct-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The cash inflow received from loan funding under the Paycheck Protection Program which was established under the Coronavirus Aid, Relief and Economic Security (CARES) Act in March 2020.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ProceedsFromPaycheckProtectionProgramUnderCaresAct" xlink:to="intt_ProceedsFromPaycheckProtectionProgramUnderCaresAct-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="us-gaap_CorporateNonSegmentMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_CorporateNonSegmentMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Corporate, Non-Segment [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CorporateNonSegmentMember" xlink:to="us-gaap_CorporateNonSegmentMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_IndependentDirectorsMember" xlink:label="intt_IndependentDirectorsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_IndependentDirectorsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Independent Directors [Member]</link:label>
    <link:label xlink:label="intt_IndependentDirectorsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the independent directors.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_IndependentDirectorsMember" xlink:to="intt_IndependentDirectorsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:label="us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense</link:label>
    <link:label xlink:label="us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Lease, Right-of-Use Asset, Amortization Expense</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:to="us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_StockholdersEquity</link:label>
    <link:label xlink:label="us-gaap_StockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total stockholders' equity</link:label>
    <link:label xlink:label="us-gaap_StockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xml:lang="en-US">Balance</link:label>
    <link:label xlink:label="us-gaap_StockholdersEquity-label" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Balance</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_ScheduleOfCarryingValueOfFinitelivedIntangibleAssetsTableTextBlock" xlink:label="intt_ScheduleOfCarryingValueOfFinitelivedIntangibleAssetsTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="intt_ScheduleOfCarryingValueOfFinitelivedIntangibleAssetsTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Carrying Value of Finite-lived Intangible Assets [Table Text Block]</link:label>
    <link:label xlink:label="intt_ScheduleOfCarryingValueOfFinitelivedIntangibleAssetsTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tabular disclosure of the carrying value of finite-lived intangible assets.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_ScheduleOfCarryingValueOfFinitelivedIntangibleAssetsTableTextBlock" xlink:to="intt_ScheduleOfCarryingValueOfFinitelivedIntangibleAssetsTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_CostsRelatedToSublettingTheFremontCAFacility" xlink:label="intt_CostsRelatedToSublettingTheFremontCAFacility" xlink:type="locator"/>
    <link:label xlink:label="intt_CostsRelatedToSublettingTheFremontCAFacility-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Costs related to subletting the Fremont, CA facility</link:label>
    <link:label xlink:label="intt_CostsRelatedToSublettingTheFremontCAFacility-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the costs related to subletting the Fremont, CA facility.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_CostsRelatedToSublettingTheFremontCAFacility" xlink:to="intt_CostsRelatedToSublettingTheFremontCAFacility-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_CovenantFutureAmountReceivable" xlink:label="intt_CovenantFutureAmountReceivable" xlink:type="locator"/>
    <link:label xlink:label="intt_CovenantFutureAmountReceivable-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_CovenantFutureAmountReceivable</link:label>
    <link:label xlink:label="intt_CovenantFutureAmountReceivable-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Covenant, Future Amount Receivable</link:label>
    <link:label xlink:label="intt_CovenantFutureAmountReceivable-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Future amount receivable if we create and maintain specified levels of employment in the specified location through various dates ending in 2023.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_CovenantFutureAmountReceivable" xlink:to="intt_CovenantFutureAmountReceivable-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_CashChargesMember" xlink:label="intt_CashChargesMember" xlink:type="locator"/>
    <link:label xlink:label="intt_CashChargesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cash Charges [Member]</link:label>
    <link:label xlink:label="intt_CashChargesMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to cash charges.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_CashChargesMember" xlink:to="intt_CashChargesMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_NonCashChargesMember" xlink:label="intt_NonCashChargesMember" xlink:type="locator"/>
    <link:label xlink:label="intt_NonCashChargesMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Non-Cash Charges [Member]</link:label>
    <link:label xlink:label="intt_NonCashChargesMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to non cash charges.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_NonCashChargesMember" xlink:to="intt_NonCashChargesMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpense" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpense" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpense-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationNondeductibleExpense</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpense-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Nondeductible expenses</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationNondeductibleExpense" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpense-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_StatementClassOfStockAxis-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Stock [Axis]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_StatementClassOfStockAxis-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_AmbrellEuropeanOperationsConsolidationMember" xlink:label="intt_AmbrellEuropeanOperationsConsolidationMember" xlink:type="locator"/>
    <link:label xlink:label="intt_AmbrellEuropeanOperationsConsolidationMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Ambrell European Operations Consolidation [Member]</link:label>
    <link:label xlink:label="intt_AmbrellEuropeanOperationsConsolidationMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to Ambrell European operations consolidation.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_AmbrellEuropeanOperationsConsolidationMember" xlink:to="intt_AmbrellEuropeanOperationsConsolidationMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Restricted stock compensation</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SeveranceAndOtherOnetimeTerminationBenefitsMember" xlink:label="intt_SeveranceAndOtherOnetimeTerminationBenefitsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_SeveranceAndOtherOnetimeTerminationBenefitsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Severance and Other One-Time Termination Benefits [Member]</link:label>
    <link:label xlink:label="intt_SeveranceAndOtherOnetimeTerminationBenefitsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information related to severance and other one-time termination benefits.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SeveranceAndOtherOnetimeTerminationBenefitsMember" xlink:to="intt_SeveranceAndOtherOnetimeTerminationBenefitsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_HeadcountReductionsAndEmployeeRelocationMember" xlink:label="intt_HeadcountReductionsAndEmployeeRelocationMember" xlink:type="locator"/>
    <link:label xlink:label="intt_HeadcountReductionsAndEmployeeRelocationMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Headcount Reductions and Employee Relocation [Member]</link:label>
    <link:label xlink:label="intt_HeadcountReductionsAndEmployeeRelocationMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to headcount reductions and employee relocation.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_HeadcountReductionsAndEmployeeRelocationMember" xlink:to="intt_HeadcountReductionsAndEmployeeRelocationMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRestructuringReserveByTypeOfCostTextBlock" xlink:label="us-gaap_ScheduleOfRestructuringReserveByTypeOfCostTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfRestructuringReserveByTypeOfCostTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Restructuring Reserve by Type of Cost [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRestructuringReserveByTypeOfCostTextBlock" xlink:to="us-gaap_ScheduleOfRestructuringReserveByTypeOfCostTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:label="us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Weighted Average Number of Shares [Table Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:to="us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SublettingCostsOfTheMansfieldMAFacilityMember" xlink:label="intt_SublettingCostsOfTheMansfieldMAFacilityMember" xlink:type="locator"/>
    <link:label xlink:label="intt_SublettingCostsOfTheMansfieldMAFacilityMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subletting Costs of the Mansfield MA Facility [Member]</link:label>
    <link:label xlink:label="intt_SublettingCostsOfTheMansfieldMAFacilityMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to the costs related to subletting the Mansfield MA facility.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SublettingCostsOfTheMansfieldMAFacilityMember" xlink:to="intt_SublettingCostsOfTheMansfieldMAFacilityMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="us-gaap_OperatingSegmentsMember" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_OperatingSegmentsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Segments [Member]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingSegmentsMember" xlink:to="us-gaap_OperatingSegmentsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_CostsRelatedToSublettingFacility" xlink:label="intt_CostsRelatedToSublettingFacility" xlink:type="locator"/>
    <link:label xlink:label="intt_CostsRelatedToSublettingFacility-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Costs related to subletting the Mansfield, MA facility</link:label>
    <link:label xlink:label="intt_CostsRelatedToSublettingFacility-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the costs related to subletting facility.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_CostsRelatedToSublettingFacility" xlink:to="intt_CostsRelatedToSublettingFacility-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_OtherMultiMarketsMember" xlink:label="intt_OtherMultiMarketsMember" xlink:type="locator"/>
    <link:label xlink:label="intt_OtherMultiMarketsMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Multi Markets [Member]</link:label>
    <link:label xlink:label="intt_OtherMultiMarketsMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information related to other multi markets.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_OtherMultiMarketsMember" xlink:to="intt_OtherMultiMarketsMember-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_NumberOfMajorCustomers" xlink:label="intt_NumberOfMajorCustomers" xlink:type="locator"/>
    <link:label xlink:label="intt_NumberOfMajorCustomers-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_NumberOfMajorCustomers</link:label>
    <link:label xlink:label="intt_NumberOfMajorCustomers-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of Major Customers</link:label>
    <link:label xlink:label="intt_NumberOfMajorCustomers-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the number of major customers accounting for 10% or more of the specified concentration risk benchmark, which includes, but not limited to, sales revenue, accounts receivable, etc.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_NumberOfMajorCustomers" xlink:to="intt_NumberOfMajorCustomers-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationTaxCredits" xlink:label="us-gaap_IncomeTaxReconciliationTaxCredits" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationTaxCredits-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationTaxCredits</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationTaxCredits-label" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Current year tax credits (foreign and research)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationTaxCredits" xlink:to="us-gaap_IncomeTaxReconciliationTaxCredits-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Domestic tax benefit, net of Federal benefit</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_SublettingCostsOfTheFremontCaFacilityMember" xlink:label="intt_SublettingCostsOfTheFremontCaFacilityMember" xlink:type="locator"/>
    <link:label xlink:label="intt_SublettingCostsOfTheFremontCaFacilityMember-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subletting Costs of the Fremont CA Facility [Member]</link:label>
    <link:label xlink:label="intt_SublettingCostsOfTheFremontCaFacilityMember-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information pertaining to subletting costs of the Fremont CA facility.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_SublettingCostsOfTheFremontCaFacilityMember" xlink:to="intt_SublettingCostsOfTheFremontCaFacilityMember-label" xlink:type="arc"/>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential" xlink:label="us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential" xlink:type="locator"/>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential</link:label>
    <link:label xlink:label="us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Foreign income tax rate differences</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential" xlink:to="us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential-label" xlink:type="arc"/>
    <link:loc xlink:href="intt-20201231.xsd#intt_DeferredGrantProceeds" xlink:label="intt_DeferredGrantProceeds" xlink:type="locator"/>
    <link:label xlink:label="intt_DeferredGrantProceeds-label" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">intt_DeferredGrantProceeds</link:label>
    <link:label xlink:label="intt_DeferredGrantProceeds-label" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deferred Grant Proceeds</link:label>
    <link:label xlink:label="intt_DeferredGrantProceeds-label" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the amount of deferred grant proceeds.</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="intt_DeferredGrantProceeds" xlink:to="intt_DeferredGrantProceeds-label" xlink:type="arc"/>
  </link:labelLink>
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