Posted: Sat Nov 12, 2005 2:45 pmHere is one equation for velocity in feet per minute from a typical Pitot tube:
V = 1096 * SQR[Pv/D]
V = Velocity in Feet per Minute (fpm)
Pv = Pressure Velocity, Differential pressure of Pitot tube impact port(s) and static pressure port(s).
D = Air Density. Usually assumed to be .0750 lbs/cubic foot for SCFM.
SQR = Square Root.
To get the volume of flow (cfm) from the velocity, multiply velocity times the cross sectional area in, square feet, of the bounded path where the Pitot tube is located.
John
V = 1096 * SQR[Pv/D]
V = Velocity in Feet per Minute (fpm)
Pv = Pressure Velocity, Differential pressure of Pitot tube impact port(s) and static pressure port(s).
D = Air Density. Usually assumed to be .0750 lbs/cubic foot for SCFM.
SQR = Square Root.
To get the volume of flow (cfm) from the velocity, multiply velocity times the cross sectional area in, square feet, of the bounded path where the Pitot tube is located.
John