Photothermal radiometric characterization of a thin deposit using a linear swept-frequency heat flux waveform

We propose a new front face thermal characterization method. The application concerns the thermal conductivity estimation of a copper oxide deposit on a tungsten carbide substrate. This method is based on the classical front face technique but in the present study the heat flux is generated as a linear swept-frequency cosine waveform. Since the thermophysical properties of the substrate are known, the thermal conductivity of the deposit is estimated from the gain values of the transfer function without measuring absolute magnitudes of the heat flux and the temperature. This approach preserves the advantages of the traditional periodic method. Additionally, the method permits performing the thermal characterization of a material from a single experiment but with much more reliability than the classical impulse method.