Ultra-wideband extensometers, mounting method thereof and calibration device

Abstract

The invention provides ultra-wideband extensometers. An ultra-wideband extensometer comprises an extensometer body, a calibration device and a protection cover. The extensometer body comprises a firstfixing end, a baseline rod, a capacitive sensor and a second fixing end. The capacitive sensor is fixed at the second fixing end. The capacitive sensor comprises two capacitive sensor stator plates and a capacitive sensor rotor plate. One end of the baseline rod is mounted on the first fixing end. The other end of the baseline rod is connected with the capacitive sensor rotor plate. The protection cover is set at outside of the extensometer body. The calibration device is set in the protection cover and is connected with the baseline rod. According to the ultra-wideband extensometer, throughdesign of the fully-sealed protection cover, the problem of influence of a temperature and an air pressure on precision of the extensometer is solved. The invention also provides a mounting method applied to the ultra-wideband extensometer and the calibration device.

Description

technical field [0001] The invention relates to the field of earth science observation, in particular to an ultra-wideband extensometer and an installation method thereof, and also relates to a calibration device. Background technique [0002] The extensometer is an instrument for precisely measuring the relative change of the horizontal distance between two points in the crustal rock mass. It is suitable for observing the continuous change of the crustal strain and the horizontal component of the solid tide. Research provides important data. [0003] In recent years, many studies have found that in the daily monitoring of seismic and solid tide stations, abnormal "pulsation" signals are often superimposed on the solid tide curve in the observation data of tiltmeters and gravimeters. The envelopes of multiple main frequency domain signals are mostly "spindle-shaped" with different durations, and they have a good corroborating relationship with broadband seismometers in this...

AI Technical Summary

Problems solved by technology

[0005] Due to the lack of accuracy of the sensor itself of the traditional extensometer, in order to improve the signal-to-noise ratio, the baseline length of the instrument is generally 20 meters. Influence of force on the instrument in the direction of measurement

This not only affects the frequency response characteristics of the instrument, but also brings measurement errors of the instrument

[0006] The existing short-baseline extensometer can theoretically achieve broadband observation, but the filter circuit still uses 60s low-pass filtering, which cannot meet the broadband observation requirements

At the same time, its accuracy and practicability are not up to the requirements through actual observations. The main influencing factors include: (1) Due to the shortening of the baseline length, the influence of temperature on the measurement accuracy increases, and the entire design does not consider the influence of temperature changes; (2) ) does not take into account the influence of air pressure on the instrument, and the influence of air pressure is obvious in actual observations, etc.

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