Flow Velocity

The inputs provided to this function block are press, autoSetOffset, and clearOffset. The output pins are flow, offset , and vel.This function computes the flow and velocity based on the measured pressure and the K factor.

flowvel.gif (1129 bytes)

and

Vel = flow/area

Where:

Analog Inputs

Range
Input Name Low High Input Value Description
press > = - infinity < + infinity unconnected output set to invalid
invalid output set to invalid
> - 0.002425 and < 0.002425 inw Flow and vel = 0
autoSetOffset > = - infinity < + infinity unconnected No effect on output
invalid No effect on output
!=0 set offset = incoming press
clearOffset > = - infinity < + infinity unconnected or invalid No effect on output
!=0 set offset = 0
area > = - infinity < + infinity Invalid or < = 0
value in ft ** 2
Velocity set to invalid
kFactor > = - infinity < + infinity unconnected output set to invalid
invalid output set to invalid
<= 0 kFactor = 1015

Output

Range
Output Name Low High Description
FLOW > = - infinity < + infinity Flow value (ft **3/min)
OFFSET > = - infinity < + infinity Input press offset correction (inches water column). Not for connection. Stores Flow offset amount.
VEL > = - infinity < + infinity Flow velocity (ft/min)