VOLUME CHANGE MEASUREMENT OF DIAPHRAGM DEFORMATION IN DIFFERENTIAL TYPE CAPACITANCE DIAPHRAGM GAUGE

摘要

A deformation of a diaphragm inside a differential type capacitance diaphragm gauge is investigated as a function of the differential pressure applied to the gauge. Below its full scale of 133 Pa, the volume change of the gauge is proportional to the applied pressure as predicted by the elastic theory. The volume change rate of the gauge is calculated to be 0.00012 ml/Pa at a line pressure of atmosphere pressure of about 100 kPa. When the pressure is more than its full scale, the response of the diaphragm volume change is linear to the applied pressure until 500 Pa. The response is changed to one-third power of the applied differential pressure as predicted by the membrane theory above 500 Pa until 3000 Pa.