Direct measurement of thermal conductivity can be complex and difficult, especially in small samples.
We determine the thermal conductivity of materials by measuring thermal diffusivity and calculating using the equation below:
Where a is the thermal diffusivity
•K is thermal conductivity
•r is density
•Cp is the specific heat (at constant pressure).
Note that conversion from thermal diffusivity to thermal conductivity requires the correction of room temperature density data for thermal expansion.
The relative ease with which it is possible to measure thermal diffusivity, makes it a useful tool for the determination of a material’s thermal conductivity.