Multi-stepwise pulse calorimetry for accurate, efficient measurements of thermophysical properties over a wide temperature range

Watanabe, Hiromichi*; Morimoto, Kyoichi ; Watanabe, Masashi  ; Kato, Masato   ; Arita, Yuji*; Konashi, Kenji*

Multi-stepwise pulse calorimetry is proposed for accurate, efficient measurements of thermophysical properties of not only ideal but also practical samples over a wide temperature range. In a single experiment for a few seconds, the sample is rapidly heated from 298 K up to the final step-temperature of around 2850 K in a multi-stepwise fashion with numerous step-temperatures, at each of which the sample attains a steady-state condition while it is maintained for an instant. The proposed calorimetry is suitable for measuring enthalpy at numerous different temperatures, because multiple enthalpy-change values between the brief steady-state conditions can be obtained in a single experiment. As a feasibility demonstration, the specific enthalpy and its uncertainty in the temperature range 10502850 K have been determined for Mo and W, respectively. The measured enthalpies and emissivities are compared with the corresponding standard data.