On the Characteritics of the Vibrating Diaphragm Vacuum gauge

A vibrating-diaphragm vacuum gauge has been developed that is available for cotinuous measurement of the pressure ranging from 10-3 to 20 Torr. The Pressue measurements have been made by two methods. One method is based on the fact that the amplitude of vibrating-diaphragm depends on the gas pressure. Following characteristics have been obtained by this method : (1) The response time is 0.06 sec at 0.2 Torr ; (2) The temperature dependence of sensitivity is 0.08%/°C at 0.2 Torr and-2%/°C at 10 Torr ; and (3) The repeatability at room temperature is less than 0.7%. The other method is on the basis of the fact that the resonance frequency of diaphragm depends on the gas pressure. The outstanding chacteristics obtained by this methad is that the gas dependence of sensitivity is a little. For example, the difference of sensitivity for air and helium gases is 4% at 10 Torr.