Supplemental Balance Sheet Disclosures - Inventories and Prepaid expenses and other current assets (Details) - USD ($)	Dec. 31, 2018	Sep. 30, 2018
Inventory valuation
Raw materials	$ 3,153,742	$ 2,892,366
Work-in-process	716,059	817,051
Finished goods	426,187	570,691
Inventories	4,295,988	4,280,108
Prepaid expenses and other current assets
Prepaid insurance	376,586	258,015
Income tax refund receivable	2,056	1,578
Other	251,689	284,641
Total prepaid expenses and other current assets	$ 630,331	$ 544,234

Carrying amount as of the balance sheet date of income taxes previously overpaid to tax authorities (such as U.S. Federal, state and local tax authorities) representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes. Also called income tax refund receivable.

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of merchandise or goods held by the company that are readily available for sale.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of unprocessed items to be consumed in the manufacturing or production process.

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Carrying amount, net of reserves and adjustments, as of the balance sheet date of merchandise or goods which are partially completed. This inventory is generally comprised of raw materials, labor and factory overhead costs, which require further materials, labor and overhead to be converted into finished goods, and which generally require the use of estimates to determine percentage complete and pricing.

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Amount of current assets classified as other.

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Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer.

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Amount of asset related to consideration paid in advance for insurance that provides economic benefits within a future period of one year or the normal operating cycle, if longer.

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