1.1 This part of ISO 22007 specifies a method for the determination of the thermal conductivity and thermal diffusivity, and hence the specific heat capacity per unit volume, of plastics. The experimental arrangement can be designed to match different specimen sizes. Measurements can be made in gaseous and vacuum environments at a range of temperatures and pressures. 1.2 This method is suitable for testing homogeneous and isotropic materials, as well as anisotropic materials with a uniaxial structure. In general, the method is suitable for materials having values of thermal conductivity, λ, in the approximate range 0,01 W⋅m−1⋅K−1 < λ < 500 W⋅m−1⋅K−1 and values of thermal diffusivity, α, in the range 5 × 10−8 m2⋅s−1 u α u 10−4 m2⋅s−1, and for temperatures, T, in the approximate range 50 K < T < 1 000 K.