Condensed Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities
Net income	$ 2,393,014	$ 2,587,767
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	1,546,661	1,205,769
Impairment of long-lived assets	0	643,604
Deferred taxes	(384,000)
Gain on disposal of assets	(20,358)	(5,100)
Stock-based compensation	1,488,304	1,774,330
Changes in operating assets and liabilities, net of business acquisition:
Accounts receivable, net	(2,413,875)	(53,619)
Inventories	1,546,081	(965,458)
Prepaid expenses and other	289,305	324,206
Accounts payable and accrued expenses	(146,317)	(2,989,849)
Net cash provided by operating activities	4,298,815	2,521,650
Cash flows from investing activities
Business acquisition	(10,350,000)
Purchases of property, plant and equipment and intangible assets	(920,356)	(1,631,127)
Proceeds from sale of property, plant and equipment	83,052	5,100
Purchases of investments	(5,403,075)	(13,279,075)
Proceeds from maturities of investments	4,444,000	6,619,000
Net cash used in investing activities	(12,146,379)	(8,286,102)
Cash flows from financing activities
Proceeds from issuance of common stock under employee stock purchase plan	297,860	334,692
Proceeds from issuance of common stock upon exercise of stock options	21,174	28,718
Tax withholding related to exercise of stock options and restricted stock vestings	(348,527)	(462,120)
Repurchase of common stock	(1,371,414)	(2,403,062)
Net cash used in financing activities	(1,400,907)	(2,501,772)
Decrease in cash and cash equivalents	(9,248,471)	(8,266,224)
Cash and cash equivalents, beginning of period	18,536,111	28,014,321
Cash and cash equivalents, end of period	9,287,640	19,748,097
Supplemental disclosures for cash flow information
Cash paid during the year for income taxes	48,987	893,483
Non-cash financing activities
Cashless exercise of stock options	$ 5,782	$ 34,268