The ability of the element to maintain its stability and integrity. Providing a barrier against flame, smoke and hot gases for 30, 60, 90 or 120 minutes.
W = Radiation
Provides integrity and stability whilst limiting the amount of radiated heat passing through the element to below 15kw/m2 measured from 1 metre away.
I=Insulation
The ability of the element to maintain its stability and integrity plus providing a barrier to heat. When measuring the temperature on the surface of the non fire side this remains below an increase of 140 degrees centigrade above ambient temperature.
