Class1 Digital Display - Manual (Page 11)

11
Example Calibration (4”)
Install a Pitot gauge and a two inch (2”) smoothbore nozzle on the deck gun.
Determine the flow rate that you want to use.
(70 PSI=994 GPM).
Start pumping water through the deck gun until the Pitot gauge reads 70 PSI.
Enter the calibration mode by bringing a magnet close to the left side of the display and
removing it three (3) times, the left decimal point should light with each switch closure.
Bring a magnet close to the right side of the display and remove it three (3) times, the
right decimal point should light with each switch closure.
The display should read
CAL
for 1/2 second and then
0
Bring the magnet close to the right side of the display and hold it, the display number
should increase. When the display reads
994
, move the magnet away from the display.
If you stop short of
994
, you must bring the magnet close to the right side, remove it and
bring it close again for the display to increase. If you pass
994
, just bring the magnet
close to the right side and hold it until the number decreases to
994
When the flow has been stable at 70 PSI for at least 10 seconds, move the magnet close
to the left side of the display and remove it.
The display should read
donE
for several seconds and then display
994
Adjust the flow so that the Pitot reads
50
, the display should read
840
Adjust the flow so that the Pitot reads
110
, the display should show
1245
All readings should be within +- 3 % of the 120 PSI value. (+-40 GPM for a 2” nozzle)
Use a Pitot nozzle flow chart to select a calibration setting. Ideally it should be a value
close to the average rate expected from the discharge.
Check your calibration with flow values that are lower and higher than the calibration
flow but within normal flow rates for the discharge.
Note:
There is a default calibration setting for 2”, 2.5”, 3”, 4” and 5” schedule 80 pipes.
Password to enter default calibration:
L R R R L L L
Scroll through the pipe sizes with the right switch and select with the left switch.
The defaults will only work with schedule 80 pipe.
Example CAL