mV offset calibrations should be carried out first, however mV offset
and mV gain calibrations can be performed separately and need not be
done consecutively.
Set the simulator to read 000mV (no signal output).‘
PUSH’ and ‘Rotate CCW’ to go to CAL. ‘PUSH’ turns on the OFFSET
(left side) LED. ‘PUSH’ again, the LED now flashes and the display shows
“live” mV input. ‘Rotate’ until 000 shows on the display and ‘SAVE’. mV
offset is now calibrated.
Rotate ‘CCW’ goes to End then ‘PUSH’ to exit. Rotate ‘CW’ proceeds
to the mV CAL (gain) calibration.
A mV gain calibration can only be performed with more than 280mV
input. The display shows
Err
if a value below these parameters is present.
If this happens ‘PUSH’ two times, the display shows “live” mV to allow the
operator to correct for a valid mV offset value. ‘PRESS’ now returns to the
calibration menu to repeat the procedure.
F
Set the simulator mV output higher than 280mV.‘
PUSH’ turns on the SLOPE (right side) LED. ‘PUSH’ again, the LED
now flashes and the display shows “live” mV input. ‘Rotate’ until the correct
mV value shows on the display and ‘SAVE’. The mV reading of the PMH-2
is now accurate.
Rotate ‘CCW’ two times goes to End then ‘PUSH’ to exit. Rotate ‘CW’
proceeds to mA calibrations. (See 4-20mA output)
Selecting Mode of Operation.
Dosing
Adding chemicals such as chlorine or bromine to water increases the
reading. The PMH-2 has to stop the pump or valve at the entered setpoint.
The reading of the water to be treated therefore is below the desired value,
(selected SET POINT) therefore dosing is set to UP.
In a situation where the reading of the water is reduced, the water to be
treated is above the desired value, (selected SET POINT) therefore
dosing is set to down.
PMH-2 Instruction manual
PAGE 21
