To meet the needs of modern firefighting, FRC Flowmasters utilize a paddlewheel sensor which is rugged, simple, and tough. The sensor is mounted into the pipe so that only a portion of the paddle extends into the flow. Flow causes the paddlewheel to rotate and its revolutions are converted into electrical signals which can be displayed.
It is resistant to damage from debris in the water because the paddle is free spinning and moves with the flow. Frequent flow calibration is not necessary when using a paddlewheel flowmeter as long as the paddle is able to spin freely.
Note: It is very important the paddlewheel flow sensor is plumbed correctly. NEVER locate the sensor after a valve. ALWAYS place the sensor BEFORE the valve! For suggested plumbing diagrams request literature on paddlewheel installation.
Accuracy Range
The following table shows the velocity that water travels in feet per second (ft/sec.)
in various pipe sizes at different GPM rates.
Assuming the sensor is properly plumbed, the Fire Research paddlewheel flow sensor will deliver its most accurate readings when the velocity of the water being measured is greater than 1.5 ft/sec. and less than 60 ft/sec. The table is filled only with those values that reflect good accuracy so you get a very nice visual picture of the Fire Research paddlewheel's accuracy range.
Example: In a 1½" pipe, the FRC paddlewheel sensor will give very accurate readings for flows between 10 and 400 GPM +/- 3gpm or +/- 1% of reading whichever is greater.
