In search of thermal effusivity reference materials

Quality initiatives such as ISO 9001 require reference values for laboratory measurements. There are no certified reference materials for the secondary material property of thermal effusivity. Reference values are derived from measurements of thermal conductivity, specific heat capacity, and density. A search of the literature is conducted to find materials with the "best' values for thermal conductivity, specific heat capacity, and density so that a table of reference values for thermal effusivity may be obtained. Tabulated thermal effusivity values range from 0.04 kW s^1/2 m⁻² K⁻¹ for expanded polystyrene board to 40 kW s^1/2 m⁻² K⁻¹ for copper metal.