EN ISO 5658-2 Reaction to fire tests-spread of flame-Part 2: Lateral spread on building products in vertical configuration
Lateral flame spread is determined on vertically oriented specimens using a rectangular radiant panel and an additional gas burner flame as the ignition source. The assessment is based on the CFE-value. The CFE-value (Critical Heat Flux at extinguishment, expressed in kW/m2) is the incident heat flux at the specimen surface at the point along its horizontal centreline where the flame ceases to advance and may subsequently go out. The CFE-value is determined by measuring the maximum spread of flame (in mm) and relating this value to the corresponding heat flux value from the heat flux profile curve which is based on measurements with a non-combustible calibration board.
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