Development of vacuum-pressure measurement device by refractivity measurement

Abstract

The pressure p is proportional to the refractive index (n_gas-1). The refractive index can be measured from the resonance frequency of the laser using a Fabry-Perot resonator. Because it is based on frequency measurement, wide range pressure measurement is possible with small uncertainty. In this research, we developed a measurement system for the pressure range from 1 Pa to 100 kPa. In this presentation we report the principle of measurement, the outline of the experimental system, and the measured linearity between the refractive index (n_gas-1) and the pressure p.