Note 5 - Revenue From Contracts With Customers - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Revenue	$ 27,884	$ 30,941	$ 32,558	$ 31,919	$ 32,405	$ 30,771	$ 29,571	$ 24,081	$ 123,302	$ 116,828
Semiconductor Market [Member]
Revenue									65,735	68,422
Industrial Market [Member]
Revenue									14,310	10,038
Automotive [Member]
Revenue									9,895	10,776
Life Sciences [Member]
Revenue									4,856	4,589
Defense/ Aerospace [Member]
Revenue									12,537	7,006
Security [Member]
Revenue									3,688	3,241
Other Multi Markets [Member]
Revenue									12,281	12,756
Thermal Testing Products [Member]
Revenue									21,344	22,246
Thermal Process [Member]
Revenue									44,914	38,574
Semiconductor Production Test Products [Member]
Revenue									30,235	28,529
Video Imaging [Member]
Revenue									9,086	9,499
Flying Probe and In-circuit Testers [Member]
Revenue									6,981	7,414
Service and Other Products [Member]
Revenue									10,742	10,566
End User [Member]
Revenue									85,397	84,468
OEM, Integrators and Distributor [Member]
Revenue									$ 37,905	$ 32,360