Thermal diffusivity and thermal conductivity of toluene by photon correlation spectroscopy: A test of the accuracy of the method

Absolute measurements of the thermal diffusivity of liquid toluene were performed by photon correlation spectroscopy between 393 and 523 K near the saturation line. The experimental method is based on a time-resolved analysis of the laser light scattered from local equilibrium fluctuations in a transparent sample. enabling us to obtain the thermal diffusivity in macroscopic thermodynamic equilibrium. The experimental results are compared with previous data obtained with the same method, with the transient-hot-wire technique. and also with calculated values of thermal dilhusivity from reference data for thermal conductivity, heat capacity, and density. They demonstrate an agreement of 2.5%. which is within the uncertainty of the reference data.Paper presented at the Twelllh Symposium on Thermophysical Properties. June 19–24. 1994, Boulder, Colorado. U.S.A.Author to whom correspondence should be addressed.