Abstract
A differential laser flash calorimeter was developed to measure specific heat capacity of solid materials up to high temperatures. The specimen to be measured is placed close to the reference specimen of known heat capacity side by side. Surfaces of both specimens are coated with the same black thin layer in order to get the same absorptance for the laser beam and the same spectral emissivity for radiation thermometry.
The front surfaces of both specimens are heated by a uniform beam from a pulse YAG laser and the change of spectral radiance from each specimen is observed with a high speed radiation thermometer. The heat capacity of the measured specimen is calculated from the ratio of the radiance change for two specimens and the heat capacity of the reference specimen.
Specific heat capacity of graphite and carbon/carbon composite was successfuly measured from the room temperature to 1700K. The measured specific heat capacity of the carbon/carbon composite is consistent with a differential scanning calorimetry measurement from the room temperature to 500K.
