The Method of Detecting the Vacuum Degree Inside the Accelerometer by Frequency Sweeping of the Servo Circuit

Abstract

The invention relates to a method for detecting the internal vacuum degree of an accelerometer through servo circuit frequency sweeping, which is technologically characterized by comprising the following steps: S1, before vacuum sealing, measuring the frequency sweeping peak amplitude inside an accelerometer through a closed-loop frequency sweeping approach, and calibrating the vacuum degree of the accelerometer; and S2, after vacuum sealing of the accelerometer, measuring the frequency sweeping peak amplitude through the closed-loop frequency sweeping approach, and comparing the vacuum degreewith the previous calibrated value, so as to compete accelerometer vacuum degree test. The vacuum degree is tested through an electrical servo circuit closed-loop frequency sweeping approach, withoutthe need to change the original design of the accelerometer. The servo circuit adopts a pure proportional amplification link, so that frequency sweeping can completely reflect the internal characteristics of acceleration, and the influence of the circuit link on calibration is reduced. The accuracy of vacuum degree measurement is improved by adjusting the gain of a proportional amplifier.

Description

technical field [0001] The invention belongs to the technical field of vacuum degree detection, and relates to a quartz flexible accelerometer for a gravity gradiometer, in particular to a method for detecting the vacuum degree inside the accelerometer by sweeping frequency of a servo circuit. Background technique [0002] In order to reduce the noise of the gravity gradiometer system, it is necessary to evacuate the interior of the accelerometer for the gradiometer and maintain it for a long time. Therefore, it is necessary to develop a practical technology for convenient and accurate detection of the vacuum inside the accelerometer, with a measurement range of 10-100Pa. [0003] At present, the methods for accurately measuring the vacuum degree inside the sealing body include the gauge measurement method and the quartz resonator measurement method. The regulation measurement method installs a special regulation inside the sealing body, applies an external voltage, and the ...

AI Technical Summary

Problems solved by technology

The quartz resonator measurement method is to apply power to the quartz resonator, and the quartz resonator will resonate. The resonant frequency changes with the change of pressure, and the pressure directly depends on the change of the vacuum degree of the surrounding environment. Therefore, it can be measured by measuring the resonant frequency. Measuring the internal vacuum degree of the sealing body, compared with the gauge measurement method, its structural volume is greatly reduced, but the installation of this structure will still change the internal structure and size of the accelerometer, thus resulting in changes in the external dimensions of the accelerometer, which will bring about system installation of the accelerometer. It is not a good choice to redesign and process the size of related structural parts

Images