Thermophysical property measurements for R1234yf + R1234ze(E) mixture

Measurements of PρTx properties, saturated densities and critical parameters for low GWP refrigerant mixtures of 50.00 mass% R1234yf (2, 3, 3, 3-tetrafluoroprop-1-ene; CF₃CF=CH₂) + 50.00 mass% R1234ze(E) (trans-1, 3, 3, 3-tetrafluoroprop-1-ene; CF₃CH=CHF) system were measured with two types of isochoric methods. As for PρTx properties, 5 isochores were obtained in the range of temperatures from 310 K to 430 K, of pressures from 837 kPa to 6774 kPa, and of densities from 100 kg·m^-3 to 900 kg·m^-3. As for the saturated densities, 9 saturated vapor densities and 6 saturated liquid densities were measured for temperatures from 354.622 K to 374.280 K and for densities between 219 kg·m^-3 and 870 kg·m^-3. On the basis of the present data, the critical temperature T_c = 374.28 K, critical density ρ_c = 480 kg·m^-3, and critical pressure P_c = 3524 kPa for 50% R 1234yf + 50% R 1234ze(E) mixture were determined by the direct observation of meniscus disappearance.