Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (1,295,587)	$ (2,321,671)
Adjustments to reconcile net loss to net cash provided by (used for) operating activities:
Depreciation	2,248,317	1,501,607
Amortization	19,104	19,104
Amortization of debt issuance costs	16,976	16,829
Deferred income taxes	24,684	462,315
Stock-based compensation	313,144	344,016
Gain on sale of assets		(700,000)
Loss on disposal of fixed assets	2,469	1,733
Changes in:
Trade accounts receivable, gross	(704,867)	411,724
Accrued interest income	(27,753)
Inventory	(186,585)	(281,939)
Prepaid expenses and other current assets	(73,749)	128,849
Other assets	(13,931)	(12,033)
Accounts payable and accrued expenses	(88,711)	80,162
Deferred revenue		(24,100)
Net cash provided by (used for) operating activities	233,511	(373,404)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(1,391,446)	(2,029,895)
Maturities of investment	7,670,000
Purchases of investments	(10,123,000)
Payment of contingent royalties related to 2016 acquisition	(8,914)	(14,077)
Proceeds from sale of assets	450,000	250,000
Net cash used for investing activities	(3,403,360)	(1,793,972)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from public offering, net	8,303,436
Proceeds from debt issuance		693,640
Proceeds from line of credit		500,000
Debt principal repayments	(861,347)	(398,308)
Line of credit repayment	(500,000)
Payments of debt issue costs		(1,971)
Proceeds from exercise of stock options	3	96,254
Net cash provided by financing activities	6,942,092	889,615
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	3,772,243	(1,277,761)
BEGINNING CASH AND CASH EQUIVALENTS	2,521,050	3,798,811
ENDING CASH AND CASH EQUIVALENTS	6,293,293	2,521,050
CASH PAID FOR:
Income taxes	3,566	4,222
Interest expense	420,956	403,535
NON-CASH ACTIVITIES:
Change in capital expenditures included in accounts payable and accrued expenses	97,530	(568,695)
Net change in fair value of interest rate swaps, net of taxes	74,052	(30,795)
Fixed asset disposals, gross	$ 62,055	$ 22,681