System Design
April 2020 3-12 06-237619-001
3-8.8 Atmospheric Correction Factors
The ambient pressure is affected by changes in altitude, therefore the extinguishant quantity
shall be multiplied, where applicable, by the correction factor (at the associated altitude) as
listed in Table 3-7.
Table 3-7. Atmospheric Correction Factors
Altitude Enclosure Pressure
Correction Factor
ft. km PSIA cm Hg
-3000 -0.92 16.25 84.00 1.11
-2000 -0.61 15.71 81.20 1.07
-1000 -0.30 15.23 78.70 1.04
0 0 14.71 76.00 1.00
1000 0.30 14.18 73.30 0.96
2000 0.61 13.64 70.50 0.93
3000 0.92 13.12 67.80 0.89
4000 1.22 12.58 65.00 0.86
5000 1.52 12.04 62.20 0.82
6000 1.83 11.53 59.60 0.78
7000 2.13 11.03 57.00 0.75
8000 2.44 10.64 55.00 0.72
9000 2.74 10.22 52.80 0.69
10000 3.05 9.77 50.50 0.66