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  <element name="DeferredRevenueAndCustomerAdvancesMaintenanceAndTraining" id="ter_DeferredRevenueAndCustomerAdvancesMaintenanceAndTraining" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
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  <element name="EbitdaMember" id="ter_EbitdaMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EmployeesMember" id="ter_EmployeesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EquityAndDebtMutualFundsMember" id="ter_EquityAndDebtMutualFundsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
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  <element name="FinancialInstrumentsAndFairValueLineItems" id="ter_FinancialInstrumentsAndFairValueLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FinancialInstrumentsAndFairValueTable" id="ter_FinancialInstrumentsAndFairValueTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="ForeignCurrencyTranslationAdjustmentsMember" id="ter_ForeignCurrencyTranslationAdjustmentsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="FourPointFiveZeroPercentConvertibleSeniorNotesDueMarchFifteenTwoThousandFourteenMember" id="ter_FourPointFiveZeroPercentConvertibleSeniorNotesDueMarchFifteenTwoThousandFourteenMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="GoodwillAndIntangibleAssetsDisclosureLineItems" id="ter_GoodwillAndIntangibleAssetsDisclosureLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="GoodwillAndIntangibleAssetsDisclosureTable" id="ter_GoodwillAndIntangibleAssetsDisclosureTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="IncomeTaxesLineItems" id="ter_IncomeTaxesLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncomeTaxesTable" id="ter_IncomeTaxesTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="IncreaseDecreaseInPrepaidExpenseAndOtherAssets" id="ter_IncreaseDecreaseInPrepaidExpenseAndOtherAssets" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IndustrialAutomationMember" id="ter_IndustrialAutomationMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LongTermContingentConsiderationMember" id="ter_LongTermContingentConsiderationMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LongTermMarketableSecuritiesMember" id="ter_LongTermMarketableSecuritiesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="MarketableSecuritiesMember" id="ter_MarketableSecuritiesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="MergerAcquisitionRestructuringAbstract" id="ter_MergerAcquisitionRestructuringAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="MinimumRetirementAgeForEligibleEmployeesOfPostretirementPlans" id="ter_MinimumRetirementAgeForEligibleEmployeesOfPostretirementPlans" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="MinimumYearsOfServiceForEligibleEmployeesOfPostretirementPlans" id="ter_MinimumYearsOfServiceForEligibleEmployeesOfPostretirementPlans" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NetIncomeLossPerCommonShareLineItems" id="ter_NetIncomeLossPerCommonShareLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
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  <element name="NumberOfTradingPeriodConsiderForWeightAveragePriceOfCommonStock" id="ter_NumberOfTradingPeriodConsiderForWeightAveragePriceOfCommonStock" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="OutperformanceRevenueEarnoutMember" id="ter_OutperformanceRevenueEarnoutMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PledgePercentageOfCapitalStock" id="ter_PledgePercentageOfCapitalStock" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PrepaidAndOtherCurrentAssetsLineItems" id="ter_PrepaidAndOtherCurrentAssetsLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PrepaidAndOtherCurrentAssetsTable" id="ter_PrepaidAndOtherCurrentAssetsTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
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  <element name="PrepaidMaintenanceAndOtherServices" id="ter_PrepaidMaintenanceAndOtherServices" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PreparationOfFinancialStatementsAndUseOfEstimatesPolicyTextBlock" id="ter_PreparationOfFinancialStatementsAndUseOfEstimatesPolicyTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RevenueEarnoutMember" id="ter_RevenueEarnoutMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScenarioOneMember" id="ter_ScenarioOneMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScenarioThreeMember" id="ter_ScenarioThreeMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScenarioTwoMember" id="ter_ScenarioTwoMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScheduleOfCarryingAmountsAndFairValuesOfFinancialInstrumentsTableTextBlock" id="ter_ScheduleOfCarryingAmountsAndFairValuesOfFinancialInstrumentsTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScheduleOfDeferredRevenueAndCustomerAdvancesTableTextBlock" id="ter_ScheduleOfDeferredRevenueAndCustomerAdvancesTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScheduleOfExtendedProductWarrantyLiabilityTableTextBlock" id="ter_ScheduleOfExtendedProductWarrantyLiabilityTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScheduleOfInterestExpenseRelatedToConvertibleDebtTableTextBlock" id="ter_ScheduleOfInterestExpenseRelatedToConvertibleDebtTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScheduleOfNetIncomeLossPerCommonShareTable" id="ter_ScheduleOfNetIncomeLossPerCommonShareTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="ScheduleOfPrepaidExpenseTableTextBlock" id="ter_ScheduleOfPrepaidExpenseTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScheduleOfSegmentReportingInformationBySegmentChargesTableTextBlock" id="ter_ScheduleOfSegmentReportingInformationBySegmentChargesTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScheduleOfShareBasedPaymentAwardShareholderReturnPlanValuationAssumptionsTableTextBlock" id="ter_ScheduleOfShareBasedPaymentAwardShareholderReturnPlanValuationAssumptionsTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SegmentReportingInformationSegmentCharges" id="ter_SegmentReportingInformationSegmentCharges" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SemiconductorTestMember" id="ter_SemiconductorTestMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ServiceBasedRestrictedStockUnitsMember" id="ter_ServiceBasedRestrictedStockUnitsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareholderReturnAwardPerformanceMeasurementPeriod" id="ter_ShareholderReturnAwardPerformanceMeasurementPeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareholderReturnPerformanceBasedRestrictedStockUnitsMember" id="ter_ShareholderReturnPerformanceBasedRestrictedStockUnitsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShortTermPurchaseCommitments" id="ter_ShortTermPurchaseCommitments" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShortTermPurchaseCommitmentTimePeriod" id="ter_ShortTermPurchaseCommitmentTimePeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="StockholdersEquityNoteDisclosureLineItems" id="ter_StockholdersEquityNoteDisclosureLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="StockholdersEquityNoteDisclosureTable" id="ter_StockholdersEquityNoteDisclosureTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="StockIssuedDuringPeriodSharesSaleOfStockAndExerciseOfStockOptions" id="ter_StockIssuedDuringPeriodSharesSaleOfStockAndExerciseOfStockOptions" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SystemsTestGroupMember" id="ter_SystemsTestGroupMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="UncategorizedAbstract" id="ter_UncategorizedAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="UnitedStatesSupplementalExecutiveDefinedBenefitPensionPlanMember" id="ter_UnitedStatesSupplementalExecutiveDefinedBenefitPensionPlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="UniversalRobotsMember" id="ter_UniversalRobotsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="WirelessTestMember" id="ter_WirelessTestMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ZtecCorporationMember" id="ter_ZtecCorporationMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
</schema>
