Application of infrared microscopy to thermal diffusivity measurement in refractories at various temperatures

An infrared microscope coupled with a mercury cadmium telluride detector is used to measure thermal diffusivity in refractory materials with a 100 mu m spatial resolution. Experimental data obtained on a pure titanium sample are compared with reference values. The agreement is good within 15% at ambient temperature and is better than +/-10% at temperatures higher than 300 degrees C. This setup was applied to a refractory used for glass manufacturing. Local diffusivity variations, consistent with the morphology and composition of the sample, are detected with a resolution better than 100 mu m.