WARRANTY RESERVES (Details) (USD $)	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Instruments [Member]	Dec. 31, 2012 Reagent Discs [Member]	Mar. 31, 2012 Reagent Discs [Member]
Product Warranty Liability [Line Items]
Period of coverage for standard warranty obligation on instruments (in years)					one to three years
Change in accrued warranty reserve [Roll Forward]
Balance at beginning of period	$ 1,480,000	$ 1,436,000	$ 1,846,000	$ 1,222,000
Provision for warranty expense	337,000	500,000	998,000	1,113,000
Warranty costs incurred	(351,000)	(331,000)	(1,088,000)	(987,000)
Adjustment to pre-existing warranties	0	0	(290,000)	257,000
Balance at end of period	1,466,000	1,605,000	1,466,000	1,605,000
Non-current portion of warranty reserve	473,000	482,000	473,000	482,000
Warranty reserve, balance at end of period						570,000	564,000
Current portion of warranty reserve	$ 993,000	$ 1,123,000	$ 993,000	$ 1,123,000		$ 570,000	$ 564,000