We developed an instrument for gas pressure calibration based on optical resonance cavities,the so-called op-tical pressure gauge.Two independent optical pressure gauges were calibrated by a piston pressure gauge with a stated uncer-tainty of 0.001 1%(A=1).The uncertainty budget of the optical pressure gauge was systematically analyzed,and the overall uncertainty of the system was obtained.The optical pressure gauge was used to calibrate a commercial capacitance di-aphragm gauge with a stated uncertainty of 0.025%several times during a period over one year.The results show that the un-certainty can reach 0.003%within one year after calibration.The results demonstrate the use of the optical gauge in calibrat-ing commercial gauges with high accuracy,and also indicate a good long-term stability of the optical pressure gauge.The in-strument therefore can be applied to calibrate various commercial pressure gauges to improve the uncertainty of actual mea-surement.
vacuum measurementpressure gaugeFabry-Perot cavitygas refractive index