Metrological aspects of thermal relaxation technique by radiation loss for volumetric heat capacity measurements
Instituto de Física de la Universidad de Guanajuato, A.P.E-143, CP 37150, León, Gto., Mexico
2 Centro Brasileiro de Pesquisas Físicas, 22290-180 Rió de Janeiro, RJ, Brasil
3 CINVESTAV-Unidad Mérida, Antigua Carretera a Progreso Km. 6, CP 97310, Mérida, Mexico
One of the best-known methods to measure the heat capacity of solids consists in the illumination of the sample and the analysis of the thermal relaxation when the illumination is stopped. In this work, the energy balance equation with heat losses due to radiation is solved exactly. This is used to establish the limits of the usual approximations used to obtain the heat capacity from the experimental data. It is shown that large temperature changes, induced by the heat source during the experiment can generate errors in the calculation of heat capacity when the traditional approach is used.
© EDP Sciences, Springer-Verlag, 2008