Analysis of two‐dimensional temperature response during the measurement of thermal diffusivity of platelike samples by an ac calorimetric method

A new method has been developed to estimate the two‐dimensional periodic temperature response of platelike samples using the Fourier transform of the two‐dimensional impulse response for the designated system. This method is applied to the case of thermal diffusivity measurements parallel to the sample surface using an ac calorimetric method. It is concluded from the theoretical consideration that the thermal system can be considered as a one‐dimensional system except at the boundary of the heated and nonheated regions. The thermal system cannot be considered as a one‐dimensional system near the boundary of the heated and nonheated regions since the ac temperature response changes transiently perpendicular to the sample surface. © 1995 American Institute of Physics.