This British Standard describes a tube furnace method for the generation of fire effluent for the identification and measurement of its constituent combustion products. It uses a moving test specimen and a tube furnace at different temperatures and air flow rates as the fire model. The method can be used to model a wide range of fire conditions by using different combinations of temperature, non-flaming and flaming decomposition conditions and different fuel/oxygen ratios in the tube furnace. These include the following types of fires, as detailed in BS 7899-2:1999, Table 8: Stage 1: Non-flaming: Stage 1b) Oxidative pyrolysis from externally applied radiation; Stage 2: Well ventilated flaming (representing a flaming developing fire); Stage 3: Less well ventilated flaming: Stage 3a) Small vitiated fires in closed or poorly ventilated compartments; Stage 3b) Post-flashover fires in large or open compartments. For each flaming fire type the minimum conditions of test are specified in terms of the equivalence ratio ϕ as follows: Stage 2: ϕ