5707070-A Installation and Operation 2-23
Sono-Trak™ Doppler Ultrasonic Flow Meter
If the flow rate readings are not as expected, these are factors that may be
contributing:
1. The meter is measuring flow with a high level of turbulence, which may be caused
by too short of a straight run for proper transducer placement.
2. The liquid being measured has high viscosity, is too thick, or contains sound
absorbing materials (for example, drilling mud).
If either of these conditions exist, and your flow readings appear inaccurate, then you
may need to adjust the K Factor (correction factor) to get the desired flow rate.
Note: The K Factor is linear. Increase the K Factor to lower the flow rate or decrease
the K Factor to increase the flow rate by the percentage that the flow is off.
Again, for most applications, the default K Factor setting ensures the most accurate
reading by your Doppler flow meter. Consult “Troubleshooting the Unit” on page 3-1
to troubleshoot inaccurate flow readings before making this adjustment.
To Set the K Factor:
1. Press the K FAC/3 key.
2. Enter Hz/ FPS. If you want to keep the default setting, enter 090.
3. After setting the K Factor, the LCD screen will return to the rate and totalizer flow
reading.
Analog Output
To Set the Analog Output:
1. Press the FPS/1 or MPS/7 key to obtain the current velocity reading in feet per
second or meters per second. Press the key again to return to the flow reading
parameters previously shown.
2. Press the MA/4 key. Using the current FPS/1 or MPS/7 reading as a guide, enter
the full scale feet per second or meters per second reading to set the output in mA.
3. After the output level has been set, the LCD screen will return to the rate and
totalizer flow reading.
Low Flow Cutoff
To Set the Low Flow Cutoff:
1. Press the FPS/1 or MPS/7 key to obtain the current reading in feet per second or
meters per second. Press the key again to return to the flow reading parameters
previously shown.
2. Press the LFC/6 key. Enter the cutoff in feet per second or meters per second. If
you enter a parameter that is too high, the LCD screen will display the maximum
allowable cutoff setting and then will return to the prompt for cutoff in feet per
second.
