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, 2019	Sep. 30, 2018
Disaggregation Of Revenue [Line Items]
Total revenue	$ 45,847	$ 53,306
Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue	45,847	53,306
Operating Segments | Oil and Gas Markets Product and Services Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	15,628	23,179
Operating Segments | Oil and Gas Markets Product and Services Revenue | Traditional Exploration
Disaggregation Of Revenue [Line Items]
Total revenue	8,712	11,795
Operating Segments | Oil and Gas Markets Product and Services Revenue | Wireless Exploration
Disaggregation Of Revenue [Line Items]
Total revenue	4,362	6,851
Operating Segments | Oil and Gas Markets Product and Services Revenue | Reservoir
Disaggregation Of Revenue [Line Items]
Total revenue	2,554	4,533
Operating Segments | Adjacent Markets Product and Services Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	30,060	29,841
Operating Segments | Adjacent Markets Product and Services Revenue | Industrial
Disaggregation Of Revenue [Line Items]
Total revenue	18,324	18,352
Operating Segments | Adjacent Markets Product and Services Revenue | Imaging
Disaggregation Of Revenue [Line Items]
Total revenue	11,736	11,489
Operating Segments | Emerging Markets Product and Services Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	$ 159	$ 286