Note 7 - Disaggregated Revenues and Segment Information - Net Revenue, Classified by Geography (Details) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Revenue from Contract with Customer, Including Assessed Tax	$ 749,654	$ 762,644	$ 2,322,871	$ 2,258,822
Chemical [Member]
Revenue from Contract with Customer, Including Assessed Tax	331,812	352,484	1,017,895	949,574
Electronics [Member]
Revenue from Contract with Customer, Including Assessed Tax	347,911	270,245	911,569	955,217
Engineering [Member]
Revenue from Contract with Customer, Including Assessed Tax	69,931	139,915	393,407	354,031
UNITED STATES
Revenue from Contract with Customer, Including Assessed Tax	669,296	673,615	2,085,019	2,046,305
UNITED STATES | Chemical [Member]
Revenue from Contract with Customer, Including Assessed Tax	251,454	263,455	780,043	737,057
UNITED STATES | Electronics [Member]
Revenue from Contract with Customer, Including Assessed Tax	347,911	270,245	911,569	955,217
UNITED STATES | Engineering [Member]
Revenue from Contract with Customer, Including Assessed Tax	69,931	139,915	393,407	354,031
Non-US [Member]
Revenue from Contract with Customer, Including Assessed Tax	80,358	89,029	237,852	212,517
Non-US [Member] | Chemical [Member]
Revenue from Contract with Customer, Including Assessed Tax	80,358	89,029	237,852	212,517
Non-US [Member] | Electronics [Member]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0	0
Non-US [Member] | Engineering [Member]
Revenue from Contract with Customer, Including Assessed Tax	$ 0	$ 0	$ 0	$ 0