Ultrashort baseline extensometer

Abstract

The present invention discloses an ultra short baseline extensometer, which relates to an extensometer. The present invention has the structure that one end of a baseline bar (130) is connected with a displacement sensor (110), which is connected with a first base rock (310) through a nulling device (120); the other end of the baseline bar (130) is connected with a calibrater (150) and then connected with a second base rock (320) through a fixed end (160); the displacement sensor (110) is respectively connected with a measurement and control system (200) through the calibrater (150); the displacement sensor (110) is a differential capacitance sensor (211) with an entire seal structure. The baseline of the present invention is not more than 100 cm, the resolving ability is superior to 1 is multiplied by 10 and then minus 10, the mechanical drive does not exist, the calibration is reliable; the extensometer can be arranged vertically; the volume is small, thus the extensometer is suitable for carrying, and adaptable to the flow of the forerunning effect of earthquake and the emergency monitoring; and the extensometer can be generalized to be used on a long baseline extensometer and other micro-displacement measuring devices.

Description

technical field [0001] The invention relates to an extensometer, in particular to an ultra-short baseline extensometer. Background technique [0002] The extensometer is an instrument for precisely measuring the relative change of the distance between two points in the crustal rock mass. It plays an important role in observing the crustal strain and solid tide and studying the process of earthquake breeding. After decades of observations using extensometers in my country, a large amount of valuable data and typical earthquake examples have been accumulated for earthquake prediction and analysis: For example, on April 22, 1992, the magnitude 6.2 earthquake in China and Myanmar, the extensometer in Panzhihua, Sichuan 28 days before the earthquake A 40mm step anomaly map appears, with a step size of 3×10 -8 "Sudden jump" and "turning point" appeared in the abnormal form of Guzan station in Sichuan. The abnormal time ranged from a few hours to 5 days, and the longest was 38 days...

AI Technical Summary

Problems solved by technology

In the early 1970s, my country successfully developed the visual extensometer, which was installed and used in several stations as the first generation observation instrument, which laid a preliminary foundation for the study of the relationship between strain and earthquake in my country, but its sensitivity and long-term stability are not very good. high

In the 1980s, Dr. Van Rombeck of the Royal Observatory of the Kingdom of Belgium developed an extensometer with a capacitive sensor. Due to the unsolved moisture-proof problem, it failed.

[0007] The DZB type ultra-micro calibration system has been used in the SS-Y extensometer, but its negative capacity is poor, it is difficult to perform overall calibration of the instrument (only sensor calibration), and it can only do large-scale calibration (about 1000 of the solid tide) Times), its structure is complex, the cost is high, it belongs to the mechanical transmission calibrator, its own volume is large, there are reasons such as friction, wear, rust, etc., which may easily cause mechanical failure, and often need to be maintained and maintained

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