Measurements of PVTx properties for binary mixtures of HFC-32 (CH2F2) and HFC-134a (CH2 FCF3)

An experimental study of pressure-volume-temperature-composition (PVTx) pro perties for binary mixtures of HFC-32 and HFC-134a was conducted in the ran ge of temperatures from 243 to 473 K, pressures up to 16.7 MPa, densities t i om 9.5 to 1065 kg . m(-3), and compositions from 0.39 to 0.89 mol Fractio n of HFC-32, with uncertainties of 8 mK, 1.7 kPa, 0.04%, and 0.001 mol frac tion, respectively. A constant-volume method was used for the present measu rements either with a spherical vessel approximately 270 cm(3) in its inner volume or with a cylindrical vessel approximately 138 cm(3) in its inner v olume. The present data were compared with the Piao equation of state for t his substance.