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3.4.2.3.2 Inert gas agents
Q= V[294/(273+T)]・(P/1.013)・ln[100/(100-C)]
where:
Q= volume of inert gas, measured at 294 K and 1.013 bar, discharged, m3
V= volume of test enclosure, m3
T= test enclosure temperature, Celsius.
P= test enclosure pressure, bar
C= gaseous agent concentration, volume per cent.
3.5 Procedure
3.5.1 Fuel levels in trays
The trays used in the test should be filled with at least 30mm fuel on a water base. Freeboard should be 150±10mm.
3.5.2 Fuel flow and pressure measurements
For spray fires, the fuel flow and pressure should be measured before and during each test.
3.5.3 Ventilation
3.5.3.1 Pre-burn period
During the pre-burn period the test enclosure should be well ventilated. The oxygen concentration, as measured at mid-room height, shall not be less than 20 volume per cent at the time of system discharge.
3.5.3.2 End of pre-burn period
Doors, ceiling hatches, and other ventilation openings should be closed at the end of the pre-burn period.
3.5.4 Duration of test
3.5.4.1 Pre-burn time
Fires should be ignited such that the following burning times occur before the start of agent discharge:
.1 sprays-5 to 15s
.2 trays-2 min
.3 crib-6 min
