Temperature corrections for the calibration of vacuum gauges

Abstract

Commercial vacuum gauges indicate pressure, although their signal is often generated proportional to other quantities of the gas like the volume density or the impingement rate of gas molecules. These different types of gauges exhibit different mathematical dependences on temperature. To compare calibration results and to use gauge readings properly, it is necessary to refer the calibration results to an agreed reference temperature, which is normally 23 °C. This report deduces the relevant equations to do the corrections properly when gauges, which are in use as secondary standards (ionisation gauges, spinning rotor gauges, capacitance diaphragm gauges), are being calibrated or used at temperatures different from the agreed reference temperature.