Measurement of thermal diffusivity of semi-transparent thin plate by phtoacoustic method

A photo-acoustic method was applied to the measurement of thermal diffusivity of thin plate which was semi-transparent for radiation. An analytical model was newly proposed to consider radiation transfer including scattering process. The calculated results indicated that the phase lag between the incident irradiation and the detected sound strongly depended on the absorption coefficient of radiation. The effects of the scattering coefficient on the phase lag were much smaller than those of the absorption coefficient. The thermal diffusivity and the absorption coefficient of color cellophane films and alumina plates could be simultaneously and properly determined based on the analysis of the measured data.