Note 14 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Net revenues	$ 33,991	$ 32,558	$ 63,815	$ 64,477
Earnings before income tax expense	296	3,365	1,083	6,759
Acquired intangible amortization	(897)	(523)	(1,492)	(1,067)
Interest expense	(253)	(176)	(393)	(358)
Other income (expense)	213	197	648	255
Operating Segments [Member]
Net revenues	33,991	32,558	63,815	64,477
Earnings before income tax expense	3,706	6,176	7,495	12,443
Operating Segments [Member] | Electronic Test [Member]
Net revenues	16,159	10,993	27,275	21,364
Earnings before income tax expense	1,743	2,641	3,556	5,219
Operating Segments [Member] | Environmental Technologies [Member]
Net revenues	8,273	8,136	15,101	16,178
Earnings before income tax expense	993	943	1,008	1,956
Operating Segments [Member] | Process Technologies [Member]
Net revenues	9,559	13,429	21,439	26,935
Earnings before income tax expense	970	2,592	2,931	5,268
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Earnings before income tax expense	$ (2,473)	$ (2,309)	$ (5,175)	$ (4,514)