Schedule II - Valuation and Qualifying Accounts - Summary of Valuation and Qualifying Accounts (Details) - USD ($)		3 Months Ended	12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2015
Allowance for Doubtful Accounts [Member]
Balance at beginning of period		$ 10,275	$ 10,000	$ 10,000		$ 10,000
Additions charged to costs and expenses	[1]		275	(1,784)		(3,255)
Additions charged to other accounts	[2]
Deductions	[3]			(1,784)		(3,255)
Balance at end of period		10,275	10,275	10,000		10,000
Inventory Valuation Reserve [Member]
Balance at beginning of period		473,252	235,592	251,500		363,500
Additions charged to costs and expenses	[4]	56,261	284,352	82,292		(47,045)
Additions charged to other accounts
Deductions	[5]	(72,008)	(46,692)	(98,200)		64,955
Balance at end of period		457,505	473,252	235,592		251,500
Warranty Reserves [Member]
Balance at beginning of period		0				9
Additions charged to costs and expenses				8,912		12,555
Additions charged to other accounts
Deductions				8,912		12,564
Balance at end of period		0	0
Valuation Allowance of Deferred Tax Assets [Member]
Balance at beginning of period		500,000	500,000	4,248,900		4,166,700
Additions charged to costs and expenses		(452,681)		(3,681,100)		82,200
Additions charged to other accounts				67,800	[6]
Deductions
Balance at end of period		47,319	500,000	$ 500,000		$ 4,248,900
Uncertain Tax Position Reserves [Member]
Balance at beginning of period
Additions charged to costs and expenses		395,000
Additions charged to other accounts
Deductions
Balance at end of period		$ 395,000

[1] Classified as bad debt expense

[2] Recoveries on accounts charged off in prior years

[3] Accounts charged off during year as uncollectible

[4] Reduction in inventory obsolescence reserve

[5] Inventory charged off during the year as obsolete

[6] Recovery of net operating loss reserve