CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Text Block [Abstract]
Sales	$ 37,193	$ 30,508
Cost of sales	(23,469)	(19,557)
Gross profit	13,724	10,951
Operating expenses:
Selling, general and administrative	(6,561)	(6,045)
Research and development	(2,851)	(2,908)
Pension	(217)	(231)
Total operating expenses	(9,629)	(9,184)
Operating income	4,095	1,767
Interest expense	(433)	(473)
Other income, net	106	76
Income before income tax benefit (expense)	3,768	1,370
Income tax benefit (expense)	(21)	111
Net income	$ 3,747	$ 1,481
Net income per common share - basic	$ 0.33	$ 0.13
Net income per common share - diluted	$ 0.31	$ 0.12
Weighted average common shares outstanding - basic	11,353	11,353
Weighted average common shares outstanding - diluted	11,978	12,014
Comprehensive income, net of tax:
Net income	$ 3,747	$ 1,481
Decrease (increase) in minimum pension liability	200	(30)
Total comprehensive income	$ 3,947	$ 1,451