The spread of flame is measured along the sides of a vertical or horizontal surface of a specimen exposed to a flame and a radiant panel. The after-glow, damaged zone and dripping are also observed.
Test method
The radiant panel and pilot flame are ignited. The burner and the vertically oriented specimen are then positioned. The time to reach the different marker threads is recorded. The average velocity is calculated to reach the flame spread velocity.The damaged zone and dripping and flaming debris are observed.Based on the observations of flame spread, damaged zone and dripping and flaming debris, the material can be classified in levels:
Level
Flame spread velocity
Damaged zone
Period of after glow
dripping
1
Not measured (flame failed to reached 3rd mark
=< 300mm
=< 180s
No drops or flaming debris
2
=< 30mm/min
> 300mm and < 600mm
>180s and < 360s
Drops or flaming debris extinguishing after 3s
3
> 30mm/min
>= 600mm
>= 360s
Drops or flaming debris not extinguishing after 3s
Result
The levels are multiplied with a factor.
Flame spread velocity à x2
Damaged zoneàx2
After-glow timeàx1
Drippingàx1 for wall x2 for ceiling
The sum of the levels of behaviour multiplied by the correction factors give the products category (I to IV).
