Note 14 - Business Segments - Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Jun. 30, 2023
Revenues	$ 12,202	$ 12,390	$ 22,168	$ 24,329
Operating Income / (loss)	677	1,069	676	2,136
Assets	46,598	46,196	46,598	46,196	$ 42,186
Depreciation and amortization	1,315	1,236	2,784	2,143
Capital expenditures	81	2,838	158	3,994
Corporate, Non-Segment [Member]
Revenues		0	0	0
Operating Income / (loss)	264	32	214	90
Assets	188	77	188	77
Depreciation and amortization	15	6	27	0
Capital expenditures	0	12	0	12
Manufacturing [Member]
Revenues	4,790	5,044	7,675	8,629
Manufacturing [Member] | Operating Segments [Member]
Revenues	4,790	5,044	7,675	8,629
Operating Income / (loss)	191	301	149	477
Assets	19,242	15,345	19,242	15,345
Depreciation and amortization	101	99	214	230
Capital expenditures	19	15	38	15
Testing Services [Member]
Revenues	4,646	5,648	9,810	12,012
Testing Services [Member] | Operating Segments [Member]
Revenues	4,646	5,648	9,810	12,012
Operating Income / (loss)	(152)	547	(280)	1,129
Assets	22,690	27,757	22,690	27,757
Depreciation and amortization	1,181	1,111	2,507	1,875
Capital expenditures	62	2,811	120	3,967
Distribution [Member]
Revenues	2,760	1,694	4,670	3,676
Distribution [Member] | Operating Segments [Member]
Revenues	2,760	1,694	4,670	3,676
Operating Income / (loss)	401	217	646	482
Assets	1,976	1,437	1,976	1,437
Depreciation and amortization	0	0	0	0
Capital expenditures	0	0	0	0
Real Estate Segment [Member]
Revenues	6	4	13	12
Real Estate Segment [Member] | Operating Segments [Member]
Revenues	6	4	13	12
Operating Income / (loss)	(27)	(28)	(53)	(42)
Assets	2,502	1,580	2,502	1,580
Depreciation and amortization	18	20	36	38
Capital expenditures	$ 0	$ 0	$ 0	$ 0