An application of the photoacoustic technique is developed for determining the thermal diffusivity and thermal conductivity of thermally thick samples by rear excitation. In the present work, thermal parameters measurements of polyvinylidene difluoride films over the temperature range from 100 K to 300 K are reported. Results regarding thermal parameters at room temperature are in very good agreement with results from the literature. In order to obtain these results we have determined the thermal parameters of quartz. To date, there do not exist in the literature data on the thermal parameter variation of polyvinylidene difluoride over the temperature range.

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Thermal diffusivity measurements in glass and Teflon are reported over the temperature range from 90 to 300 K. The results are obtained by multifrequency rear surface excitation combined with impulse response determination using correlation photopyroelectric techniques. A simple and versatile computer-based system performing generation of given excitation wave forms, data acquisition, and analysis is described. A one-dimensional model is proposed in order to explain the experimental results.