Test Report on the Model 44000 Seismometer System
Abstract
Teledyne Geotech has completed long period subsurface vault tests on four individual 44000 modules; two horizontal and two vertical. Each type of module is tested in tandem by comparing the outputs of aligned sensors. The latest data is outstanding, particularly that of the horizontal. At a period of 20 seconds, both vertical and horizontal channels show incoherent noise power of approximately-180 dB relative to 1 (m/sec-sq)sq/Hz. At a period of 64 seconds, the horizontal data is some 20 dB quieter than any previous borehole data and furthermore shows no increase with period, even at periods as long as 250 seconds. This performance is remarkable for a non-borehole installation. The vertical data shows excellent performance, although some temperature effects seem to be present. A detailed explanation of the experimental history and current tests follows.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1988
- Accession Number
- ADA199900
Entities
Organizations
- Teledyne Technologies