Pulse calorimetry at high temperatures

Pulse-heating techniques have been developed in the last 30 years to overcome difficulties of steady-state experiments in the high temperature range. In these methods the specimen is pulse-heated to high temperatures in short times (typically less than 1 s) using Joule heating and the various experimental quantities are measured with millesecond to microsecond time resolution. Many thermophysical properties are measurable with these methods, including heat capacity, melting point and enthalpy of fusion. In the high temperature range (above 1000 K) these absolute techniques provide accurate calorimetric data and have been used to characterize different materials taking advantage of the possibility to determine several properties in a single experiment of subsecond duration. The state-of-the-art of pulse calorimetry is reviewed making reference to the apparatus developed at the Istituto di Metrologia “G. Colonnetti” (IMGC, Torino, Italy), with a particular emphasis on the characterization of some reference materials (molybdenum, tungsten and platinum) in the temperature range 1000–3600 K.