Dielectric properties of liquid pentafluoroethane (HFC-125)

This paper reports measurements of the static relative permittivity of HFC- 125 in the liquid phase, performed by using the direct capacitance method a t 10 kHz, for temperatures from 214 to 304 K and pressures up to 16 MPa. Th e repeatability of the measurements was found to be of the order of +/-0.7 x 10(-3) and the uncertainty is estimated to be better than +/-0.72 x 10(-2 ). We provide a complete set of tables of experimental data as a function o f temperature, pressure, and density, which cover the dielectric property n eeds for most engineering applications. The data obtained were used to esta blish dielectric equations of state as a function of density and temperatur e and as a function of pressure and temperature. To study the dependence of the relative permittivity on temperature, pressure and density, we have ap plied various molecular theories of polar liquids. The apparent dipole mome nt obtained was mu* = 2.482 D.