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	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Disaggregation Of Revenue [Line Items]
Total revenue	$ 21,565	$ 21,604	$ 34,597	$ 48,326
Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue	21,565	21,604	34,597	48,326
Operating Segments | Oil and Gas Markets
Disaggregation Of Revenue [Line Items]
Total revenue	12,111	13,885	16,876	24,940
Operating Segments | Oil and Gas Markets | Traditional Exploration Product Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	1,217	790	1,797	1,787
Operating Segments | Oil and Gas Markets | Wireless Exploration Product Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	10,500	12,630	14,258	22,659
Operating Segments | Oil and Gas Markets | Reservoir Product Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	394	465	821	494
Operating Segments | Adjacent Markets
Disaggregation Of Revenue [Line Items]
Total revenue	9,155	7,554	17,285	14,424
Operating Segments | Adjacent Markets | Industrial Product Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	5,993	4,977	11,006	9,384
Operating Segments | Adjacent Markets | Imaging Product Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	3,162	2,577	6,279	5,040
Operating Segments | Emerging Markets
Disaggregation Of Revenue [Line Items]
Total revenue	$ 299	$ 165	$ 436	$ 8,962