Note 5 - Disaggregated Revenues and Segment Information - Net Revenue, Classified by Geography (Details) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Net revenues	$ 805,126	$ 739,538	$ 2,592,738	$ 2,351,201
Chemical [Member]
Net revenues	295,262	281,431	1,095,543	1,068,299
Electronics [Member]
Net revenues	430,114	181,779	866,091	430,486
Engineering [Member]
Net revenues	79,750	276,328	631,104	852,416
UNITED STATES
Net revenues	766,182	662,263	2,311,512	2,026,387
UNITED STATES | Chemical [Member]
Net revenues	256,318	204,156	814,317	768,485
UNITED STATES | Electronics [Member]
Net revenues	430,114	181,779	866,091	405,486
UNITED STATES | Engineering [Member]
Net revenues	79,750	276,328	631,104	852,416
Non-US [Member]
Net revenues	38,944	77,275	281,226	324,814
Non-US [Member] | Chemical [Member]
Net revenues	38,944	77,275	281,226	299,814
Non-US [Member] | Electronics [Member]
Net revenues				25,000
Non-US [Member] | Engineering [Member]
Net revenues