Characterization of a black paint layer by photothermal lock-in thermography
The Hankel integral transform is used to interpret the radial temperature distribution at the surface of a black paint coating on a steel substrate, under irradiation by a modulated laser beam. An inverse method based on the Gauss-Newton algorithm allows the identification of the coating thermal conductivity. To avoid difficulties due to the great number of thermographic data, we present estimations realized directly in the Hankel domain. The black paint coating reveals to be significantly insulating, with a thermal diffusivity of 7.5 10-8 m².s-1 .
D.LEGAIE, H.PRON, C.BISSIEUX
Reçu le 22 juin 2007.
Accepté le 8 octobre 2007.
Photothermal infrared thermography, integral transform method, parameter identification, non destructive evaluation, lock-in detection, paint layer thermal conductivity
Anglais
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