Product Warranties (Tables)

9 Months Ended

Jun. 30, 2018

Product Warranties [Abstract]

Schedule of Product Warranty Liability [Table Text Block]

Changes in the Company's warranty liability (included in accrued expenses) for the three and nine month periods ended June 30, 2018 and 2017 were as follows:

	Three Months Ended June 30,						Nine Months Ended June 30,
	2018			2017			2018			2017
Balance at beginning of period	$	431,000		$	650,000		$	431,000		$	650,000
Provision for warranties	68,000			107,000			221,000			323,000
Expenses incurred	(68,000		)	(107,000		)	(221,000		)	(323,000		)
Balance at end of period	$	431,000		$	650,000		$	431,000		$	650,000