Thermal Diffusivity Measurements of Thermographite

This paper presents results of measurements of a graphite proposed to serve as a thermophysical property reference or standard reference material. The reported measurements contribute to a program launched in 1999 by AInter Corp. with the objective to provide a replacement for the NIST thermal property reference material RM AXM-5Q graphite whose supplies were being exhausted. Measurements of the thermal diffusivity performed on five specimens taken from different positions within a large graphite block between room temperature and 1300 K were in good mutual agreement. Measurements of NIST reference AXM- 5Q graphite sample supplied to minimize effects of different contributors to a common base were also in good agreement, both with the NBS reference function established by Hust in 1984 and contributions to the NBS project from the Vincˇa Institute of Nuclear Sciences carried out in 1979. The influence of different data reduction techniques on the measured thermal diffusivity values is illustrated and discussed.