Note 9 - Segment and Related Information (Detail) - Information by industry segment is set forth below: (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012	Sep. 30, 2012
Net Sales
Net Sales	$ 1,964,338	$ 1,178,538	$ 3,703,241	$ 2,360,039
Income (Loss) before provision for Income Taxes
Income (Loss) before Provision for Income Taxes	119,431	(224,781)	263,235	(407,921)
Asset Information
Asset Information	3,511,817	3,446,149	3,511,817	3,446,149	3,205,971
Indicators and Gauges [Member]
Net Sales
Net Sales	417,607	352,372	827,833	730,375
Income (Loss) before provision for Income Taxes
Income (Loss) before Provision for Income Taxes	113,216	44,125	224,840	101,590
Asset Information
Asset Information	807,464	759,865	807,464	759,865
Automotive Diagnostic Tools and Equipment [Member]
Net Sales
Net Sales	1,546,731	826,166	2,875,408	1,629,664
Income (Loss) before provision for Income Taxes
Income (Loss) before Provision for Income Taxes	297,435	(45,700)	604,900	(60,956)
Asset Information
Asset Information	1,398,266	1,575,177	1,398,266	1,575,177
General Corporate Expenses [Member]
Income (Loss) before provision for Income Taxes
Income (Loss) before Provision for Income Taxes	(291,220)	(223,206)	(566,505)	(448,555)
Total [Member]
Income (Loss) before provision for Income Taxes
Income (Loss) before Provision for Income Taxes	119,431	(224,781)	263,235	(407,921)
Asset Information
Asset Information	3,511,817	3,446,149	3,511,817	3,446,149
Corporate [Member]
Asset Information
Asset Information	1,306,087	1,111,107	1,306,087	1,111,107
United States [Member]
Revenue:
Geographical Information - Revenue	1,896,250	1,143,642	3,596,685	2,256,275
Australia [Member]
Revenue:
Geographical Information - Revenue	14,231	23,556	14,231	35,609
Canada [Member]
Revenue:
Geographical Information - Revenue	22,644		50,698	13,752
Mexico [Member]
Revenue:
Geographical Information - Revenue	3,488	10,080	10,536	20,160
Taiwan [Member]
Revenue:
Geographical Information - Revenue	22,481	1,260	22,481	33,665
Other Foreign Countries [Member]
Revenue:
Geographical Information - Revenue	5,244		8,610	578
Total [Member]
Revenue:
Geographical Information - Revenue	$ 1,964,338	$ 1,178,538	$ 3,703,241	$ 2,360,039