ABSTRACT
Hot Disk measurements, based on the TPS-(Transient Plane Source)-technique, is being used for determining the thermal conductivity and the thermal diffusivity of solids. The specific heat can be calculated from the ratio of these two transport coefficients. This kind of measurements presuppose an initially isothermal sample with a total temperature increase that varies between 0.1 K and 1.0 K.
In this work solid samples are placed inside a thermally insulated holder made of a material with high thermal conductivity. The holder with the sample is exposed to a constant output of power from a Hot Disk sensor attached to the holder. The experiment is carried out over periods of time which are long compared with the time it takes to establish non-varying temperature gradients inside the holder and sample assembly. During the heating period the temperature increase of the sensor is continuously recorded by following its resistance increase. Indications from a series of measurements on metallic and ceramic samples at room temperature are that it is possible to conveniently estimate the specific heat of a solid with an accuracy of a few percent.
