Simple-pendulum absolute gravimeter based on two-point fixed differential measurement

Abstract

The invention discloses a simple-pendulum absolute gravimeter based on two-point fixed differential measurement, which comprises a vacuum cavity, a metal wire, a quality inspector, two pairs of knife-edge fixtures, two pairs of horizontal displacement adjusting devices, a displacement sensor, an oscillator and two length reference blocks, wherein the metal wire is respectively clamped through the two pairs of knife-edge fixtures; the knife-edge fixtures are shifted through the displacement adjusting devices so as to fix a first suspension point and a second suspension point; the length reference blocks are used for adjusting the vertical distance between the two pairs of knife-edge fixtures; and the displacement sensor is used for detecting the motion displacement of the quality inspector. According to the invention, due to the fixed measurement idea through the two suspension points at different heights, the suspension points at different heights are respectively fixed through the two pairs of knife-edge fixtures; therefore, the problem of directly measuring the absolute pendulum length is solved; direct measurement of the relative pendulum length is easier to realize; furthermore, influence of the pendulum length caused by the external environment and indefinite suspension points is effectively reduced; the measurement precision of the relative pendulum length is 10-7 m; therefore, the precision of measuring the g value through single pendulum is increased and can be up to mGal level.

Description

technical field [0001] The invention belongs to the field of gravitational acceleration measuring instruments, and more specifically relates to a single pendulum absolute gravimeter based on two-point fixed differential measurement. Background technique [0002] Acceleration of gravity is an important physical constant. Accurate measurement of acceleration of gravity is of great significance in the fields of earth science, basic physics, and engineering applications. Gravity measurement is divided into gravity acceleration measurement and gravity gradient measurement, in which gravity acceleration measurement can be divided into absolute measurement and relative measurement, and the corresponding instruments are called absolute gravimeter and relative gravimeter respectively. The absolute gravimeter refers to the measurement of the absolute magnitude of the acceleration of gravity g, and the commonly used methods are the pendulum method (including the simple pendulum method ...

AI Technical Summary

Problems solved by technology

[0010] Aiming at the defects of the prior art, the object of the present invention is to provide a single pendulum absolute gravimeter based on two-point fixed differential measurement, aiming to solve the problem that the prior art is difficult to measure the length change of the pendulum length with high precision and poor repeatability. question

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