The Influence Of Temperature On The Performance And Output Of Very-broadband Seismometer

Seismological observation, which is an important part of geophysical observation, is the basisfor the development of seismology and geophysics. With the constant development ofGeodynamics and Digital Seismology, seismologists attach more and more attention to the quality ofobservation seismic data. High-precision seismic observation device and stable and suitable stationenvironment, as well as regular calibration for the station instrument, are the important premise andguarantee to obtain high quality seismic data.At present, seismometers with large dynamic range and broadband have become themainstream instrumentation for seismological observation. Broadband seismometer and verybroadband seismometer have been greatly used in China's Seismological Observation System. Thewidely use of Long period seismic observation instrument, proposes more and more demandingrequirements for the observation environment of seismic stations. The temperature factor ofseismic stations has been a hot research topic for the seismic observation in recent years. Materialperformance and elements' precision of the earthquake observation instruments are sensitive to thetemperature factor. And the influence of temperature on the Performance of precision measuringinstrument, including earthquake observation instruments, is universal and cannot be ignored.However, the effects of temperature on long period signal of seismic observation are onlyqualitative analyzed. Hardly one type of seismic observation instruments could give instrumenttemperature curve quantitatively. And the quantitative analysis on seismic meter output effected oftemperature effects on little information. The quantitative research data on the influence oftemperature on the output of seismometer are rare.Based on above reasons, this thesis systematically studied the influence of temperature on thevery-broadband seismometer form a quantitative point of view for the first time. It mainlydiscusses the effect from the following two aspects: temperature effect on sensitivity of verybroadband seismometer, the influence of temperature on the output of seismometer (includingfrequency and level). Based on the above goals, this paper studies the testing method on theinfluence of temperature on broadband seismometer, and the analysis method on the effect oftemperature on the output of broadband seismometer. The author designed the temperature measurement circuit board with the character of low drift, high resolution (0.0005℃) for seismicstation, obtaining the internal high resolution temperature data synchronously while theseismometer is testing in the seismic station. Taking Very broadband seismometer BBVS-120asexperimental object, the author carried out static test of temperature effect at laboratory andobservation test in seismic station.Through laboratory experiment, the author summed up the influence of temperature on thesensitivity and amplitude frequency characteristics of very broadband seismometer BBVS-120, anddescribes the instrument temperature characteristic curve quantitatively for the first time, providinga certain reference for scientific evaluation on the effect of temperature about the very broadbandseismometer. Through observation experiment in seismic station, the author quantitatively studiesthe effect of temperature on the frequency band range of the seismometer's output signal and thetemperature sensitivity parameter for the first time, and describes the effect of temperature on thelong period signal of seismic observation.In this paper, the author just takes the very broadband seismometer BBVS-120as an example,systematically studying the testing and analysis method about the influence of temperature on theseismometer. The results have confirmed the relevant cognition and experience obtained inlong-term observation.The test and analysis method on the temperature effect are universally true for otherearthquake instruments, which can be applied to the study effect of temperature on other seismicobservation instrument. The author hope the conclusion of this thesis could provide the certainreference for the seismic observation, the improvements of seismic design, and the quantitativeevaluation temperature effect of on very-long-period seismic signals.