1.1 ,This test method covers the determination of the thermal diffusivity of carbons and graphite at temperatures up to 500 ,°,C. It requires only a small easily fabricated specimen. Thermal diffusivity values in the range from 0.04 ,cm²/s to 2.0 ,cm²/s are readily measurable by this test method, however, for the reason outlined in Section 7, for materials outside this range this test method may require modification.