Note 14 - Business Segments - Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Jun. 30, 2022
Revenues	$ 12,390	$ 10,922	$ 24,329	$ 21,093
Operating Income / (loss)	1,069	656	2,136	1,626
Assets	46,196	42,552	46,196	42,552	$ 43,421
Depreciation and amortization	1,236	769	2,143	1,502
Capital expenditures	2,838	357	3,994	795
Corporate, Non-Segment [Member]
Revenues	0	0	0	0
Operating Income / (loss)	32	(133)	90	(230)
Assets	77	74	77	74
Depreciation and amortization	6	0	0	0
Capital expenditures	12	0	12	0
Manufacturing [Member]
Revenues	5,044	3,528	8,629	7,090
Manufacturing [Member] | Operating Segments [Member]
Revenues	5,044	3,528	8,629	7,090
Operating Income / (loss)	301	(48)	477	252
Assets	15,345	14,799	15,345	14,799
Depreciation and amortization	99	104	230	208
Capital expenditures	15	35	15	95
Testing Services [Member]
Revenues	5,648	4,966	12,012	9,566
Testing Services [Member] | Operating Segments [Member]
Revenues	5,648	4,966	12,012	9,566
Operating Income / (loss)	547	588	1,129	1,124
Assets	27,757	24,546	27,757	24,546
Depreciation and amortization	1,111	644	1,875	1,251
Capital expenditures	2,811	322	3,967	699
Distribution [Member]
Revenues	1,694	2,420	3,676	4,418
Distribution [Member] | Operating Segments [Member]
Revenues	1,694	2,420	3,676	4,418
Operating Income / (loss)	217	277	482	531
Assets	1,437	1,850	1,437	1,850
Depreciation and amortization	0	0	0	2
Capital expenditures	0	0	0	0
Real Estate Segment [Member]
Revenues	4	8	12	19
Real Estate Segment [Member] | Operating Segments [Member]
Revenues	4	8	12	19
Operating Income / (loss)	(28)	(28)	(42)	(51)
Assets	1,580	1,283	1,580	1,283
Depreciation and amortization	20	21	38	41
Capital expenditures	$ 0	$ 0	$ 0	$ 1