Thermal diffusivity of the alternative refrigerant R152a

The thermal diffusivity of R152a was measured by dynamic light scattering, We have developed tin apparatus which enables us to apply both homodyne and heterodyne light-scattering techniques allowing a wide region of state to be investigated. A total of 300 data points was obtained along the critical isochore. in both coexisting phases and on seven isotherms with densities and temperatures ranging front 50 to 1000 kg. m -~ and 290 to 425 K, respectively. The uncertainty of the measurements lies between 0,5 and 5%, The thermaldiffusivity values cover a range of over four orders of magnitude and include the region around the vapor liquid critical point. Other measured properties tire temperature, pressure, and refractive index as well as the critical parameters T~ and p,.