1.1 ,This test method supplements Test Method C201, and shall be used in conjunction with that test method to determine the thermal conductivity of refractory brick with the exception of insulating firebrick (use Test Method C182) and carbon refractories (use Test Method C767). This test method is designed for refractories having a conductivity factor of not more than 200 Btu·,in./h·,ft²·,°,F (28.8 W/m·,K).