Speed of sound in liquid R134a

Abstract

The speed of sound for liquid R134a (1,1,1,2-tetrafluoroethane) has been measured along isotherms at temperatures from close to the triplee point to above the critical temperature (180–380 K) at pressures from near saturation to 70 MPa. The measurements were made by using a pulse-echo-overlap technique at 3 MHz. A rational approximant fits the data with a standard deviation of 0.45 m s −1. Because the speed of sound depends on the molar volume and the adiabatic compressibility, these data may be used with density and heat capacity data to construct accurate thermodynamic property tables.