A Capacitive Gauge for the Accurate Measurement of High Pressures

TLDR: In this article, the authors presented a highly accurate and precise pressure gauge, which utilizes the 35°C, 2005 Hz dielectric constant of an ionic crystal CaF2, and was calibrated at the National Bureau of Standards over the pressure range 0-2.5 kilobars.

Abstract: A highly accurate and precise pressure gauge, which utilizes the 35°C, 2005 Hz dielectric constant of an ionic crystal CaF2, is presented. The prototype gauge was calibrated at the National Bureau of Standards over the pressure range 0–2.5 kilobars, and the defining equation was found to be C/C0=1−AP+BP2, where C0 is the zero pressure capacitance, C is the capacitance at absolute pressure P, and the characteristic constants A and B are A=3.7801×10−6/(bar) and B=2.739×10−11/(bar)2. The gauge is stable and accurate over this range at the 0.01% level, and indications are that this type of gauge may be useful at much higher pressures and refined to even higher accuracies.