Geographic Information (Tables)

6 Months Ended

Nov. 30, 2016

Geographic Information Disclosure [Abstract]

Revenue from External Customers by Geographic Areas [Table Text Block]

	Six Months Ended November 30,				Three Months Ended November 30,
	2016		2015		2016		2015
Revenues from sales to unaffiliated customers:
United States	$	398,000	$	405,000	$	172,000	$	218,000
Asia		1,292,000		852,000		716,000		419,000
Europe		1,018,000		1,092,000		464,000		473,000
South America		30,000		49,000		14,000		32,000
Middle East		91,000		54,000		53,000		23,000
Other		13,000		--		13,000		--
	$	2,842,000	$	2,452,000	$	1,432,000	$	1,165,000