Volume ratio determination in static expansion systems by means of a spinning rotor gauge

Abstract

Static or volume expansion systems are used to generate accurately known pressures in the high and medium vacuum range for vacuum gauge calibrations. To determine the volume ratios in such systems, different methods can be used. We have tested the method of using a spinning rotor gauge for measuring pressures before and after an expansion for several gases and compared it with two other independent methods. The results of the volume ratios obtained with the spinning rotor gauge method were in agreement (relative differences ≤3×10 -4) with the results obtained with either of the two other methods.