Helium Research Center internal report

This report describes the apparatus and operating procedures presently being used to determine dielectric constants for gases and gas mixtures to 65 atmospheres from 35℗ʻ to -20℗ʻ Celsius. Dielectric constants and Clausius-Mosotti functions are tabulated in an appendix for He-CÓ mixtures at three temperatures in the range. The apparatus provides data of sufficient accuracy for calculation of dielectric virial coefficients over wide temperature ranges in a region where little or no data are now available. This report is intended to serve as an internal record of the equipment used and of the procedures followed to measure capacitance, pressure, and temperature.