Research On Measurement Technology Of Low Vacuum Degree In Charged Particles Environment

In some special vacuum environment in chemical and pharmacy industry, there exists a great amount of charged particles and water vapour. Conventional methods for measurement of vacuum degree are sensitive to these situation and the precision of the measurement will be greatly affected. Since it will cause the decrease of production efficiency and product quality, this problem needs to be solved urgently. Based on the analysis of the influence of charged particles as well as other factors on the measurement accuracy of conventional vacuum gauge, this paper proposed a scheme in which a electron screening was used for ordinary capacitance diaphragm vacuum gauge to prevent charged particles from being collected by the gauge. With the help of finite-element analysis, heating and insulation structures were designed to improve the sensor accuracy. A set of system of small-scale and modular circuit for both vacuum degree and temperature measuring and controlling was designed and simulated. It was a single-chip based system that could measure and display vacuum degree at a certain pre-set constant temperature. Experiments showed that the measurement of this system was accurate and low cost. The research could be of certain reference for the low vacuum degree measuring under special environment.