Photothermal method of measurement of the heat conduction

The photothermal method of heat conduction measurement is presented. Light impulse is used for sample excitation. Light energy is absorbed and is used for sample heating. This heating results in a temperature change. The thermal gradients result in heat transport. The acoustic wave velocity for accurate measurements of the temperature changes is used in this method. A case of linear dependence between temperature and acoustic wave velocity is considered. Acoustic wave is generated and detected by piezoelectric transducer. Measurements of acoustic wave velocity are made during the temperature relaxation time. The received data are used for calculation of heat conduction of a sample. The measurements were carried out by pulse method. The acoustic waves of ultrasonic frequency were used. The different converters measure the velocity of an acoustic wave in different places of the sample. Change distribution temperature of the sample corresponds accordingly heat conduction. The measurement of temperature allows to define heat conduction. The numerical modeling was used for the analysis of this method.