1.1 Scope. 1.1.1* This test method measures the response of materials exposed to controlled levels of radiant heating, with or without an external igniter. A.1.1.1 Conducting tests without piloted ignition is best kept for research and development. This method is similar to the test method contained in ASTM E 1354, Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Calorimeter (Cone Calorimeter), and in ISO 5660, Reaction-to- Fire Tests—Heat Release, Smoke Production and Mass Loss Rate— Part 1: Heat Release Rate (Cone Calorimeter Method). 1.1.2 This test method determines the ignitibility, heat release rate, mass loss rates, effective heat of combustion, and visible smoke development of materials and products. 1.1.3* This test method tests the specimen in the horizontal orientation. A.1.1.3 Testing of materials in the horizontal orientation is preferred, especially for regulatory purposes, because such testing is much more reproducible and repeatable than testing performed in the vertical orientation and generally appears to provide a more severe exposure condition. When vertical orientation is used, it is more difficult to control the pyrolysates that evolve from the material’s surface for the purpose of external ignition using the point source spark igniter. Convective heat flow along the exposed surface of the sample is also a complicating factor.