Modulated Spot Heating for the Measurement of Thermal Diffusivity

The method described in this article performs thermal diffusivity measurements on bulk materials using a modulated spot heating of the sample surface and measuring the surface temperature on the spot with an infrared detector at different modulation frequencies. Since the method is single sided and it can be performed on a bulk, it does not require the preparation of a sample. Furthermore it does not require a precise alignment nor a movement of the heating source nor of the infrared detector. The diffusivity measurement on a sample of unknown thermal diffusivity requires the knowledge of the shape of the heating and of the sensitivity profile of the infrared detector on the sample surface. This information, difficult to obtain, is not necessary in case a first measurement is performed on a reference sample of known thermal diffusivity and subsequent measurements on samples of unknown thermal diffusivity are performed by positioning them with their surface precisely in the same location as the reference one.JRC.I.4-Nanotechnology and Molecular Imagin