Anemostat EST - Manual (Page 22)

22
Altitude Correction Factors
Barometric
Pressure
Altitude Density Correction
(in h.g.) (feet) lb/ft3 Factor
29.92 0 .075 1.03
20.28 500 .074 1.01
28.85 1000 .072 0.99
28.33 1500 .071 0.98
27.82 2000 .070 0.96
27.32 2500 .068 0.95
26.81 3000 .067 0.93
26.33 3500 .066 0.91
25.84 4000 .065 0.89
25.37 4500 .064 0.88
24.89 5000 .062 0.86
24.44 5500 .061 0.85
23.98 6000 .060 0.83
23.54 6500 .059 0.82
23.09 7000 .058 0.80
Example: Determine the airflow sensor signal of a 6” unit at
500 CFM located at an elevation of 5000 ft., for a 3000 series
pneumatic controller.
To use the correction factor:
Correction factor X CFM at unit location = .86 x 500 = 430 CFM
Referencing the 6” flow curve, shown on page 10, find
430 CFM @ .80” w.c. sensor signal pressure. The velocity
controller set at .80” signal pressure will result in
500 CFM at 5000 ft. elevation.