Note 14 - Segment Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Package Testing Segment [Member]
Revenue	$ 26,583	$ 28,071	$ 25,241
Gross profit	14,445	13,850	11,919
Income (Loss) before income taxes	2,703	1,515	679
Capital expenditures	951	630	667
Depreciation and amortization	1,545	1,715	1,689
Interest expense	119	186	299
Intangible assets, net	7,053	8,781	10,986
Total assets	27,918	25,633
Permeation Segment [Member]
Revenue	25,069	23,380	21,395
Gross profit	14,415	14,985	13,438
Income (Loss) before income taxes	4,527	4,296	3,338
Capital expenditures	517	653	970
Depreciation and amortization	$ 789	$ 730	$ 629
Interest expense
Intangible assets, net	$ 1,869	$ 1,954	$ 1,656
Total assets	15,648	21,071
Industrial Analyzers and Other Segment [Member]
Revenue	9,572	13,024	10,472
Gross profit	4,364	7,279	5,912
Income (Loss) before income taxes	(1,722)	818	407
Capital expenditures	149	132	167
Depreciation and amortization	$ 126	$ 110	$ 115
Interest expense
Intangible assets, net	$ 64	$ 96	$ 76
Total assets	$ 3,853	$ 5,805
Corporate and Unallocated Segment [Member]
Revenue
Gross profit
Income (Loss) before income taxes	$ (1,049)	$ (3,171)
Capital expenditures
Depreciation and amortization
Interest expense
Intangible assets, net
Total assets
Revenue	$ 61,224	$ 64,475	$ 57,108
Gross profit	33,224	36,114	31,269
Income (Loss) before income taxes	4,459	3,458	4,424
Capital expenditures	1,617	1,415	1,804
Depreciation and amortization	2,460	2,555	2,433
Interest expense	119	186	299
Intangible assets, net	8,986	10,831	$ 12,718
Total assets	$ 47,419	$ 52,509