Applications of AC calorimetry and differential phase calorimetry in the measurement of heat capacity and phase transitions

摘要

AC calorimetry has been used for many years as a precise technique for measuring the heat capacity of small specimens over a broad temperature range. Because measurements can be undertaken at near zero heating or cooling rates, second and higher order phase transitions can be observed and interpreted with high precision. More recently a differential form of the AC calorimeter has been developed to provide a means to attain additional precision, especially on fluids available only in very small amounts. The techniques are described together with various applications of their use from cryogenic to high temperatures.