PVTx measurements in the gas phase for binary mixtures of HFC-161 and HFC-227ea

The gaseous PVTx properties of ethyl fluoride (HFC-161) + 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) mixtures were measured at temperatures from 318.180 to 403.205 K and corresponding pressures from 961.3 to 3129.8 kPa using the isochoric method. The uncertainties in the present measurements were estimated to be ±1.5 kPa for pressure and ±6 mK for temperature. On the basis of the experimental PVTx property data, a truncated virial equation of state was developed for the binary HFC-161/227ea system. This equation reproduced the experimental data in the gas phase within ±0.164% in pressure and within ±0.178% in density.