Note 14 - Business Segments - Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023
Revenues	$ 9,966	$ 11,939
Operating Income / (loss)	(1)	1,067
Assets	44,699	43,805	$ 44,699	$ 43,805	$ 42,186
Depreciation and amortization	1,471	882
Capital expenditures	77	1,156	77	1,156
Corporate, Non-Segment [Member]
Revenues	0	0
Operating Income / (loss)	(50)	(221)
Assets	374	151	374	151
Depreciation and amortization	12	0
Capital expenditures	0	0
Manufacturing [Member]
Revenues	2,885	3,585
Manufacturing [Member] | Operating Segments [Member]
Revenues	2,885	3,585
Operating Income / (loss)	(42)	176
Assets	18,996	12,791	18,996	12,791
Depreciation and amortization	114	97
Capital expenditures	19	0
Testing Services [Member]
Revenues	5,164	6,364
Testing Services [Member] | Operating Segments [Member]
Revenues	5,164	6,364
Operating Income / (loss)	(128)	861
Assets	21,312	27,770	21,312	27,770
Depreciation and amortization	1,326	767
Capital expenditures	58	1,156
Distribution [Member]
Revenues	1,910	1,982
Distribution [Member] | Operating Segments [Member]
Revenues	1,910	1,982
Operating Income / (loss)	245	265
Assets	1,958	1,603	1,958	1,603
Depreciation and amortization	0	0
Capital expenditures	0	0
Real Estate Segment [Member]
Revenues	7	8
Real Estate Segment [Member] | Operating Segments [Member]
Revenues	7	8
Operating Income / (loss)	(26)	(14)
Assets	2,059	1,490	$ 2,059	$ 1,490
Depreciation and amortization	19	18
Capital expenditures	$ 0	$ 0