Transient hot plate method with two temperature measurements for thermal characterization of metals

This paper presents a study of the transient hot plate method with simultaneous measurements of front (heated) and rear face temperatures. In contrast to the classical device, a single sample of the material to be thermally characterized is set in contact with a planar heating element and inserted between two pieces of insulating material. The purpose was to simultaneously estimate thermal effusivity and conductivity of metals in a limited time t2 ( 30 s. The thermal effusivity is estimated between 0 and t1 by minimization of the quadratic errors between the experimental curve and the simulated curve T0(t). The thermal conductivity is estimated between 0 and t2 by minimization of the quadratic errors between the experimental curve and the simulated curve T2(t). To validate the model and the estimation process, experimental tests were realized on four samples of metals with conductivities varying from 6 to 140 W m−1 °C−1 and having typical area 44.5 × 44.5 mm2 and thickness varying from 16.7 to 80 mm.