The Study Of Integrated Capacitive Pressure Measurement Device

Making a comprehensive survey about the developing small and medium-caliber artillerytechnology and the development of the corresponding chamber pressure test technology athome and abroad, our country's chamber pressure test technology has lagged far behind theforeign country, especially the volume of the pressure test instrument is larger, not intelligentenough, and the sensors used are still high-cost foreign piezoelectric crystal sensors madeabroad.These are seriously hindering China's small and medium-caliber artillery technologicalprogress. In recent years, capacitive sensor technology has matured in pressure testapplication, and there are many examples of multitudinous production, therefore, thetechnology applied to small and medium-caliber anti-aircraft anti-missile artillery pressuretest is one of the schemes worth exploring.Based on the development of these technologies, the laboratory presented the explorationof integrated capacitive pressure measurement devices. The shell against pressure of themeasurement device is a metal conductor, plus a fixed metal shell inside the shell againstpressure, it becomes a single capacitor as a pressure-sensitive components, namely,integration of the shell against pressure and the sensor, it makes the shell have anotherpurpose, the volume of the pressure measurement device is greatly reduced, and also the costof the sensor.The difficulty and key point in designing the integrated capacitive pressure measurementdevice is the sensor design and weak signal extraction, this is the focus of the content of thisarticle.This topic has analyzed theoretically the advantages of capacitive sensors, mechanicalstructure, working principle, static and dynamic characteristics, has analyzed the structuredesign of the shell of pressure measurement device and ANSYS mechanical simulation resultswhich predecessors did, has calculated the initial capacitance value and capacitance value range of the shell of pressure measurement device. On these basis, the feasibility study of theintegrated capacitive pressure measurement device is done. The design of small capacitancedetection circuit is one of the keys and difficulties in designing capacitive pressuremeasurement device, it's most difficult to taking the high-resolution and high sampling rateinto account at the same time. The author analyzed the mainstream program of today'smicro-capacitance detection, proposed small capacitive sensing program based onPS?21,designed the hardware circuit and procedure of detection system, achieved staticmicro-capacitance detection in pF level, and the circuit is used for static calibration ofpressure measurement device, proved that the principle of the integrated capacitive pressuremeasurement device is correct, worth exploring.