A direct reduction procedure for gas density determination of R143a from acoustic measurements
Maurizio Grigiante, Giancarlo Scalabrin, Giuliana Benedetto, Roberto M Gavioso, Renato Spagnolo
Measurements of the speed of sound in the vapour phase of 1,1,1-trifluoroethane (HFC-143a) are presented. The measurements were performed in a stainless-steel spherical resonator of ~900 cm3 at temperatures (T) between 270 K and 350 K and at pressures (p) up to 500 kPa. The experimental apparatus is described. Ideal-gas heat capacities and acoustic virial coefficients are directly deduced from the data. The results of these measurements are utilised to develop a virial equation of state with high accuracy, which represents the (p, r, T) surface of the vapour phase in the same temperature and pressure ranges, with density r.