EXPERIMENTAL INVESTIGATION OF THERMAL NOISE
Abstract
The primary objective of the experimental investigation of thermal noise was to verify and apply an analysis derived by National Bureau of Standards which can spectrally describe thermal energy in seismographs. When applied to a typical, operational, long-period seismograph, the NBS analysis shows the need for 10 kg inertial mass for a system magnification of about 130 k at 25 sec. Two experiments were designed to verify the NBS analysis. The first experiment was conducted to determine and verify the thermal energy spectrum for a seismometer or galvanometer connected to a resistive load. As a result of excessive uncancelled seismic inputs, the first experiment was only partially successful. The second experiment was conducted to determine and verify the thermal energy spectrum of the galvanometer in a seismometer-galvanometer combination. The results of the second experiment were agreement with theory. There was sufficient agreement between the empirical and theoretical spectra to the validity of the NBS analysis. The NBS analysis was therefore recommended for present use, but repetition of the first experiment in a seismically quieter location was recommended to further verify the analysis.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 20, 1967
- Accession Number
- AD0815676
Entities
People
- Wayne Trott
Organizations
- Geotech Instruments (United States)