THERMAL-DIFFUSIVITY AND SOUND-VELOCITY OF TOLUENE OVER A WIDE TEMPERATURE-RANGE

The thermal diffusivity and the sound velocity of toluene have been de termined in a wide temperature range up to the critical point by dynam ic light scattering. Measurements were performed for both the liquid a nd the vapor phase at saturation conditions. The results obtained corr oborate the usefulness of the technique for the determination of therm ophysical properties. From the lack of reference data for the thermal diffusivity or other properties from which the thermal diffusivity may be derived in the high-temperature range and from deviations of exper imental sound velocity data compared to values derived from the curren tly established equation of state, the need for further experimental i nvestigations on this important reference fluid was established.