Revenue Recognition - Summary of Revenue from the Sale of Products and Performance of Services Under Contracts with Customers Excludes All Revenue Earned from Rental Contracts by Operating Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Total revenue	$ 34,136	$ 45,847
Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue	34,136	45,847
Operating Segments | Oil and Gas Markets Product and Services Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	8,075	15,628
Operating Segments | Oil and Gas Markets Product and Services Revenue | Traditional Exploration
Disaggregation Of Revenue [Line Items]
Total revenue	5,849	8,712
Operating Segments | Oil and Gas Markets Product and Services Revenue | Wireless Exploration
Disaggregation Of Revenue [Line Items]
Total revenue	1,421	4,362
Operating Segments | Oil and Gas Markets Product and Services Revenue | Reservoir
Disaggregation Of Revenue [Line Items]
Total revenue	805	2,554
Operating Segments | Adjacent Markets Product and Services Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	25,327	30,060
Operating Segments | Adjacent Markets Product and Services Revenue | Industrial
Disaggregation Of Revenue [Line Items]
Total revenue	15,622	18,324
Operating Segments | Adjacent Markets Product and Services Revenue | Imaging
Disaggregation Of Revenue [Line Items]
Total revenue	9,705	11,736
Operating Segments | Emerging Markets Product and Services Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	$ 734	$ 159