Novel pulse calorimetry taking nonuniform temperature distribution into account

A novel method for measuring the specific heat capacity by pulse heating has been developed to avoid the uncertainty due to nonuniform temperature distribution across a whole effective sample during the cooling period. This method restricts determining the heat capacity to the value corresponding to the peak temperature of the sample and uses the sample itself as a resistance thermometer to measure the effective temperature of the cooling sample. To measure the resistance of the cooling sample, a low current is applied to the sample even during the cooling by using field-effect transistors as the switching device of the pulse circuit. The specific heat capacity and electrical resistivity of molybdenum at temperatures above 1700K have been measured. Electrical resistivity measurements can also be corrected by a simple uncertainty estimation that involves comparing the resistivities measured at the end of heating and at the beginning of cooling, a further advantage of this method.