SIMPLE AND INEXPENSIVE FLASH TECHNIQUE FOR DETERMINING THERMAL-DIFFUSIVITY OF CERAMICS

A simple technique for determining the thermal diffusivity of ceramics at room temperature is presented. The technique is a variant of the well-known flash technique, but uses an inexpensive photo flash as the energy source, a fast-response paste-on thermocouple, and a precision digital voltmeter to measure the temperature rise. A data analysis technique, which does not need any knowledge of either the initial or the maximum sample temperature, is presented. Good agreement with the laser-flash technique for ceramics with thermal diffusivities in the range 0.5 x 10(-6) to 75 x 10(-6) m2.s-1 is obtained. Measurements of thermal diffusivity of stainless steel and graphite (standard reference materials) indicate that the method is accurate to within 3%.