Thermal Diffusivity and Sound Speed of the Refrigerant R143a (1,1,1-Trifluoroethane)

The thermal diffusivity and the sound speed of the refrigerant R143a (1,1,1-trifluoroethane) have been determined in the temperature range 273 to 346 K by dynamic light scattering (DLS), a method based on the time-resolved analysis of scattered light intensities, which are caused by microscopic density fluctuations in the sample. The results for R143a are discussed in detail in comparison to data available in the literature. With the help of reference data for the thermal conductivity and density, the experimental data of the thermal diffusivity also allow the derivation of the isobaric heat capacity for both phases under saturation conditions.