Development of a Thermal Diffusivity Reference Material

Abstract

Polycrystalline alumina "REFERCERAM AL1" developed by the Japan Fine Ceramics Center has been studied as a candidate of thermal diffusivity reference materials. lt was experimentally confirmed that REFERCERAM AL1 is homogeneous and stable enough to be used as a reference material. Two specimens with different thickness (2mm and 3mm)were measured twice in the temperature range from R. T. to 1000K and the reference equation of thermal diffusivity was determined. Uncertainty of the reference equation was evaluated based on "Guide to the Expression of Uncertainty in Measurement(GUM)". The uncertainty of the equation consists of the relative uncertainty associated with material inhomogeneity of 1.61% and the relative uncertainty associated with the measurement of 2.29%. Then relative combined standard uncertainty is 2.80%(1σ)and the relative expanded uncertainty is derived as 5.60% with the coverage factor of "2"(2σ).