Ingenious Method for Eliminating Effects of Heat Loss in Measurements of Thermal Diffusivity by ac Calorimetric Method

To eliminate the heat loss effects in thermal diffusivity measurements using the ac calorimetric method, it is proposed theoretically that simultaneous measurement of the effective thermal diffusivities from both the amplitude decay of the ac temperature waves propagating along the surface of a thin sample and its phase shift will solve the problem, i.e., the square root of the product of the two effective thermal diffusivities is equal to the true thermal diffusivity. This is verified experimentally in the measurements for a stainless steel film and a copper film.