Components of Net Deferred Income Tax Asset (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Deferred income tax assets:
Allowance for doubtful accounts	$ 84	$ 2,816
Inventories	8,042	7,842
Loss and tax credit carry-forwards	32,523	22,027
Stock-based compensation	398	506
Accrued product warranty	79	54
Contingent earn-out consideration	917
Accrued compensated absences	320	328
Property and equipment	487	501
Prepaid income taxes	266	517
Other reserves	125	1,018
Deferred Tax Assets, Gross, Total	43,241	35,609
Deferred income tax liabilities:
Allowance for doubtful accounts		(11)
Inventories	(6)
Right-of-use assets	(131)
Intangible assets	(642)	(960)
Property, plant and equipment and other	(5,121)	(3,302)
Subtotal deferred income tax assets	37,341	31,336
Valuation allowance	(37,372)	(31,363)
Net deferred income tax assets (liabilities)	(31)	(27)
U.S.
Deferred income tax assets:
Allowance for doubtful accounts	80	2,813
Inventories	8,042	7,809
Loss and tax credit carry-forwards	27,578	17,431
Stock-based compensation	398	506
Accrued product warranty	77	52
Contingent earn-out consideration	917
Accrued compensated absences	320	328
Other reserves	114	1,009
Deferred Tax Assets, Gross, Total	37,526	29,948
Deferred income tax liabilities:
Right-of-use assets	(131)
Intangible assets	(642)	(960)
Property, plant and equipment and other	(5,085)	(3,271)
Subtotal deferred income tax assets	31,668	25,717
Valuation allowance	(31,668)	(25,717)
Non U.S.
Deferred income tax assets:
Allowance for doubtful accounts	4	3
Inventories		33
Loss and tax credit carry-forwards	4,945	4,596
Accrued product warranty	2	2
Property and equipment	487	501
Prepaid income taxes	266	517
Other reserves	11	9
Deferred Tax Assets, Gross, Total	5,715	5,661
Deferred income tax liabilities:
Allowance for doubtful accounts		(11)
Inventories	(6)
Property, plant and equipment and other	(36)	(31)
Subtotal deferred income tax assets	5,673	5,619
Valuation allowance	(5,704)	(5,646)
Net deferred income tax assets (liabilities)	$ (31)	$ (27)