NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Goodwill and Intangible Asset Impairment [Abstract]
Number of reportable segments	3
Goodwill [Line Items]
Goodwill beginning of period	$ 20,798,913
Goodwill acquired during the period	0
Goodwill end of period	20,798,913	20,798,913
Amortized intangible assets [Abstract]
Gross Carrying Amount	1,552,417	1,523,044
Accumulated Amortization	(816,564)	(713,971)
Indefinite-lived Intangible Assets [Line Items]
Amortization Expense	102,593	107,851	52,017
Estimated Amortization Expense [Abstract]
January 31, 2014	82,117
January 31, 2015	81,671
January 31, 2016	80,724
January 31, 2017	79,057
January 31, 2018	75,724
Thereafter	336,560
Total	735,853
Asset Available for Sale
Land available-for-sale Heerenveen, The Netherlands	567,459	546,771
Advertising [Abstract]
Advertising costs	1,354,995	1,258,220	988,217
Research and Development [Abstract]
Research and development costs	2,155,025	2,512,923	2,242,052
Dividends payable [Abstract]
Quarterly dividend per share (in dollars per share)	$ 0.0725
Dividend payable date	Mar. 15, 2013
Dividends payable record date	Mar. 01, 2013
Dividends payable	1,068,862
Cash paid during the year for [Abstract]
Interest	167,619	192,971	210,497
Income taxes	3,258,500	2,394,238	2,096,789
Trademarks [Member]
Indefinite-lived Intangible Assets [Line Items]
Unamortized intangible assets	11,963	11,963
Patents [Member]
Amortized intangible assets [Abstract]
Gross Carrying Amount	791,194	761,821
Accumulated Amortization	(197,855)	(131,665)
Customer Lists [Member]
Amortized intangible assets [Abstract]
Gross Carrying Amount	384,000	384,000
Accumulated Amortization	(288,167)	(275,667)
Estimated useful life	10 years
Intellectual Property [Member]
Amortized intangible assets [Abstract]
Gross Carrying Amount	195,886	195,886
Accumulated Amortization	(195,886)	(195,886)
Estimated useful life	10 years
Other [Member]
Amortized intangible assets [Abstract]
Gross Carrying Amount	181,337	181,337
Accumulated Amortization	(134,656)	(110,753)
Product Recovery/Pollution Control Technologies [Member]
Goodwill [Line Items]
Goodwill beginning of period	15,706,667
Goodwill acquired during the period	0
Goodwill end of period	15,706,667
Fluid Handling Technologies [Member]
Goodwill [Line Items]
Goodwill beginning of period	11,542
Goodwill acquired during the period	0
Goodwill end of period	11,542
Mefiag Filtration Technologies [Member]
Goodwill [Line Items]
Goodwill beginning of period	1,732,482
Goodwill acquired during the period	0
Goodwill end of period	1,732,482
Filtration/Purification Technologies [Member]
Goodwill [Line Items]
Goodwill beginning of period	3,348,222
Goodwill acquired during the period	0
Goodwill end of period	$ 3,348,222
Minimum [Member] | Patents [Member]
Amortized intangible assets [Abstract]
Estimated useful life	6 years
Minimum [Member] | Other [Member]
Amortized intangible assets [Abstract]
Estimated useful life	2 years
Maximum [Member] | Patents [Member]
Amortized intangible assets [Abstract]
Estimated useful life	20 years
Maximum [Member] | Other [Member]
Amortized intangible assets [Abstract]
Estimated useful life	20 years
Building and improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years
Building and improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	39 years
Machinery and equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	5 years
Machinery and equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years
Furniture and fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	5 years
Furniture and fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	7 years
Automotive equipment [Member]
Property, Plant and Equipment [Line Items]
Useful life	3 years