Segment Information - Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2020
Segment Reporting Information [Line Items]
Total sales	$ 14,088	$ 16,883	$ 25,476	$ 33,741
Sales:
Income (loss) from operations	(121)	(143)	(658)	(545)
Total assets	59,420	53,511	59,420	53,511	$ 53,645
Capital expenditures	10	33	43	240
Depreciation and amortization	98	114	202	239
High Performance Products Segment
Segment Reporting Information [Line Items]
Total sales	888	1,475	2,444	2,516
Sales:
Income (loss) from operations	(1,339)	(1,024)	(2,193)	(2,287)
Total assets	8,098	8,685	8,098	8,685
Capital expenditures	1	29	7	63
Depreciation and amortization	45	57	93	115
TS
Segment Reporting Information [Line Items]
Total sales	13,200	15,408	23,032	31,225
Sales:
Income (loss) from operations	1,218	881	1,535	1,742
Total assets	51,322	44,826	51,322	44,826
Capital expenditures	9	4	36	177
Depreciation and amortization	53	57	109	124
Product
Segment Reporting Information [Line Items]
Total sales	10,976	13,146	19,384	26,705
Product | High Performance Products Segment
Segment Reporting Information [Line Items]
Total sales	716	922	1,892	1,689
Product | TS
Segment Reporting Information [Line Items]
Total sales	10,260	12,224	17,492	25,016
Service
Segment Reporting Information [Line Items]
Total sales	3,112	3,737	6,092	7,036
Service | High Performance Products Segment
Segment Reporting Information [Line Items]
Total sales	172	553	552	827
Service | TS
Segment Reporting Information [Line Items]
Total sales	2,940	3,184	5,540	6,209
U.K. | TS
Segment Reporting Information [Line Items]
Total sales	331	268	1,821	947
Sales:
Income (loss) from operations	(66)	(50)	(35)	(47)
Total assets	10,497	10,757	10,497	10,757
Depreciation and amortization				3
U.K. | Product | TS
Segment Reporting Information [Line Items]
Total sales	241	184	1,644	737
U.K. | Service | TS
Segment Reporting Information [Line Items]
Total sales	90	84	177	210
U.S. | TS
Segment Reporting Information [Line Items]
Total sales	12,869	15,140	21,211	30,278
Sales:
Income (loss) from operations	1,284	931	1,570	1,789
Total assets	40,825	34,069	40,825	34,069
Capital expenditures	9	4	36	177
Depreciation and amortization	53	57	109	121
U.S. | Product | TS
Segment Reporting Information [Line Items]
Total sales	10,019	12,040	15,848	24,279
U.S. | Service | TS
Segment Reporting Information [Line Items]
Total sales	$ 2,850	$ 3,100	$ 5,363	$ 5,999