Density and speed of sound of R-406A refrigerant in the vapor phase

The speed of sound and the density of the gaseous R-406A refrigerant within the temperature range $293$–$373$ K and at the pressures from $0.05$ MPa up to $0.6$–$2.3$ MPa were investigated by means of an ultrasound interferometer and a constant volume piezometer. The measurement errors for the temperature, the pressure, and the speed of sound were $\pm20$ mK, $\pm4$ kPa, and $\pm(0.1$–$0.3)\%$, respectively. The approximation dependences of the investigated properties of the R-406A vapor are obtained and their errors are estimated. The obtained results are compared with the calculations using the REFPROP software.