5.1 This test method is intended for the determination of the heat transfer performance value of a material, a combination of materials, or a comparison of different materials used in flame resistant clothing for workers exposed to combined convective and radiant thermal hazards.

5.2 This test method evaluates a material’s unsteady-state heat transfer properties when exposed to a continuous and constant heat source. Air movement at the face of the specimen and around the calorimeter can affect the measured heat transferred due to forced convective heat losses. Minimizing air movement around the specimen and test apparatus will aid in the repeatability of the results.

5.3 This test method maintains the specimen in a static, horizontal position and does not involve movement except that resulting from the exposure.

5.4 This test method specifies a standardized 84 ± 2 kW/m² (2 ± 0.05 cal/cm²s) exposure condition. Different exposure conditions have the potential to produce different results. Use of other exposure conditions that are representative of the expected hazard are allowed but shall be reported with the results along with a determination of the exposure energy level stability.

5.5 This test method does not predict skin burn injury from the heat exposure.