AC CALORIMETRY APPLIED TO POWDERED SAMPLES - SIMULATION AND TESTS

This paper reports a home-made AC calorimeter designed for C(p) measurements on powdered samples. The results of tests with SiC and Al2O3 at constant temperature demonstrated that it is possible to measure C(p) for powdered samples with the same accuracy as for substances. usually analysed by AC calorimetry (liquids and single-crystals). The results obtained with the AC method agreed with those determined with the inverse filtering technique. This indicates that this technique is also suitable for C(p) measurements at constant temperature or with a very low scanning rate. The experimental system was simulated by a localized-constant model (RC model). This model allows analysis of the range of frequency and scanning rate values appropriate for the measurements.