1.1 ,This test method covers a steady-state technique for the determination of the thermal conductivity of carbon materials in thicknesses of less than 25 ,mm. The test method is useful for homogeneous materials having a thermal conductivity in the approximate range 1<, λ, <, 30 W/(m·,K), (thermal resistance in the range from 10 to 400 ×, 10^−,4 m² ·,K/W) over the approximate temperature range from 150 ,K to 600 ,K. It can be used outside these ranges with reduced accuracy for thicker specimens and for thermal conductivity values up to 60 ,W/(m·,K).