DIELECTRIC-CONSTANT OF ENVIRONMENTALLY ACCEPTABLE REFRIGERANTS HFC-134A, HCFC-123 AND HCFC-141B UNDER HIGH-PRESSURES

New experimental data on the dielectric constant of environmentally acceptable fluorocarbons HFC-134a (CH2F-CF3), HCFC-123 (CHCl2-CF3) and HCFC-141b (CH3-CCl2F) are presented as functions of temperature, pressure and density. The measurements were performed with a frequency-counting method and an LCR-meter method on a relative basis at temperatures from 298 to 348 K under pressures up to 35 MPa. The uncertainties of the measurements are estimated to be within 0.3% in the gaseous phase and 0.7% in the liquid phase. Experimental data at constant temperatures axe correlated with pressure by polynomials and the Owen-Brinkley equation. The effects of temperature, pressure, and density on the dielectric constant and the molar polarization defined by the Clausius-Mossotti function are discussed.