Measurement of the In-plane Thermal Diffusivity of Materials by Infrared Thermography

A transient method using the Laplace transform for estimation of the in-plane thermal diffusivity of low conductive materials is presented. The temperature field of the sample is measured by infrared thermography. The main interest of the technique proposed here is to not require a knowledge of the stimulation and boundary conditions by using two reference temperature profiles. The parameter estimation is implemented in the time domain by an inverse technique using numerical Laplace inversion and convolution products. A sensitivity study has been carried out to optimize the choice of the two reference profiles. The effect of a space varying heat transfer coefficient on the estimated values of the unknown parameters has also been evaluated. Finally, the apparatus is described and experimental results obtained for a low conductive material like a vitroceramic are shown.