Zero shift in the differential capacitance diaphragm gauges due to the change in line pressure

Abstract

This paper describes the results of experiments concerning the effect of line pressure on the zero stability of the differential capacitance diaphragm manometers. It is observed that in capacitance manometers with single-sided configuration, the zero shift value varies with different gases for a particular line pressure change and is directly proportional to the dielectric constant of the gases. For the four sensors studied, it is found that the zero shift is positive in nature and varies linearly with the change in line pressure. The linear relationship obtained on the basis of the experimental results is found useful in determining the zero shift values for any gas at any line pressure change. The zero shift at different line pressures with various gases in differential capacitance diaphragm manometers is of great importance for the metrological applications.