Fire Safety Science Digital Archive

Tests have been made with a smoke measuring apparatus that can be attached to combustion chambers such as the Fire Propagation Test Apparatus. The results of tests with wood fibre insulating board and some plastics boards and sheets have indicated the salient factors that need to be met by a smoke measuring apparatus of this form for standard acceptance tests. These are the prevention of deposition of soot and consequent restriction of the smoke path, and adequate dilution and cooling of the smoke to ensure condensation of volatiles. It is also important that the material under test can be retained in the position where it is subjected to heat in the combustion chamber. The material under test should be subjected to a wide range of conditions of combustion to ensure that smoke measurements are made under conditions producing the densest smoke. The extent to which the test, as developed so far, meets these factors is discussed, and the inherent limitations of the method are considered.