Condensed Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities
Net income	$ 637,782	$ 1,784,451
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	989,912	800,136
Deferred taxes	(384,000)
Loss (gain) on disposal of assets	1,594	(5,100)
Stock-based compensation	969,081	1,183,911
Changes in operating assets and liabilities, net of business acquisition:
Accounts receivable, net	78,265	(115,011)
Inventories	354,984	(1,597,722)
Prepaid expenses and other	(71,117)	234,201
Accounts payable and accrued expenses	(313,921)	(2,296,544)
Net cash provided by (used in) operating activities	2,262,580	(11,678)
Cash flows from investing activities
Business acquisition	(10,350,000)
Purchases of property, plant and equipment and intangible assets	(516,341)	(1,064,936)
Proceeds from sale of property, plant and equipment		5,100
Purchases of investments	(4,181,075)	(10,166,075)
Proceeds from maturities of investments	3,469,000	5,568,000
Net cash used in investing activities	(11,578,416)	(5,657,911)
Cash flows from financing activities
Proceeds from issuance of common stock under employee stock purchase plan	148,259	169,500
Proceeds from issuance of common stock upon exercise of stock options	17,949	28,459
Tax withholding related to exercise of stock options	(9,262)	(10,326)
Repurchase of common stock	(236,024)	(49,352)
Net cash (used in) provided by financing activities	(79,078)	138,281
Decrease in cash and cash equivalents	(9,394,914)	(5,531,308)
Cash and cash equivalents, beginning of period	18,536,111	28,014,321
Cash and cash equivalents, end of period	9,141,197	22,483,013
Supplemental disclosures for cash flow information
Cash paid during the year for income taxes	23,987	416,750
Non-cash financing activities
Cashless exercise of stock options	$ 5,782	$ 34,268