Dielectric Properties of Liquid Pentafluoroethane (HFC-125)

Abstract

This paper reports measurements of the static relative permittivity of HFC-125 in the liquid phase, performed by using the direct capacitance method at 10 kHz, for temperatures from 214 to 304 K and pressures up to 16 MPa. The repeatability of the measurements was found to be of the order of ±0.7×10⁻³and the uncertainty is estimated to be better than ±0.72×10⁻². We provide a complete set of tables of experimental data as a function of temperature, pressure, and density, which cover the dielectric property needs for most engineering applications. The data obtained were used to establish dielectric equations of state as a function of density and temperature and as a function of pressure and temperature. To study the dependence of the relative permittivity on temperature, pressure and density, we have applied various molecular theories of polar liquids. The apparent dipole moment obtained wasμ*=2.482 D.