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
is the zero pressure capacitance, C
is the capacitance at absolute pressure P
, and the characteristic constants A
.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.