Note 6 - Revenue From Contracts With Customers - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue	$ 30,941	$ 30,771	$ 95,418	$ 84,423
Semiconductor Market [Member]
Revenue	18,476	19,170	54,992	48,969
Industrial Market [Member]
Revenue	2,456	2,130	8,399	7,859
Automotive [Member]
Revenue	1,775	1,621	5,914	7,971
Life Sciences [Member]
Revenue	1,330	1,715	3,978	3,583
Defense/ Aerospace [Member]
Revenue	3,392	1,914	10,121	4,830
Security [Member]
Revenue	967	871	2,869	2,239
Other Multi Markets [Member]
Revenue	2,545	3,350	9,145	8,972
Thermal Testing Products [Member]
Revenue	4,742	5,836	16,734	16,844
Thermal Process [Member]
Revenue	11,518	11,026	33,212	27,990
Semiconductor Production Test Products [Member]
Revenue	8,573	7,770	25,432	20,409
Video Imaging [Member]
Revenue	1,945	2,447	7,027	6,692
Flying Probe and In-circuit Testers [Member]
Revenue	2,012	1,605	4,588	5,359
Service and Other Products [Member]
Revenue	2,151	2,087	8,425	7,129
End User [Member]
Revenue	21,139	21,548	64,720	60,785
OEM and Integrators [Member]
Revenue	$ 9,802	$ 9,223	$ 30,698	$ 23,638