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-tri- fluoroethane) 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 iIntensities, which are caused by microscopic density fluctua- tions 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 ther- mal 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.