An Apparatus for Specific Heat Capacity Measurement by Thermal Radiation Calorimetry

Specific heat capacity measurements of disk-shaped specimens have been performed with an apparatus based on thermal radiation calorimetry. The specimen surfaces were irradiated by two fiat heaters in a vacuum chamber so that homogeneous temperature distribution within an insulating specimen was achieved. Homogeneity was confirmed by computer simulation based on the control-volume method. The values of specific heat capacity were obtained by measurement of the specimen temperature, the time rate change of the specimen temperature, and the radiant power from the heater for heating and cooling modes. The specific heat capacities of Ni metal, A1₂O₃ ceramic, MgO ceramic, and A1N ceramic were measured in the temperature range from 220 to 500°C to confirm the validity of this calorimeter. The relative error involved in the measured values was estimated to be ±3%.