Installation and operating manual for WATERFRIEND exclusive MRD-2 Page 24 (44)
Calibrating
Procedure:
Press the "MENU" key
Move the cursor (blue backed text) to the line "set ORP" by pressing the keys
or
.
Press the
OK
key.
Move the cursor (blue backed text) to the line "calibration" by pressing the keys
or
.
Press the
OK
key.
The ORP electrode is immersed in the 468mV buffer solution.
The current value for the ORP electrode is then shown in the
display.
The discrepancy between the displayed value and
the buffer solution value (468mV) should not exceed ± 10
%. If there is a large discrepancy or extended reaction
time, the electrode should be replaced as soon as
possible.
If the value shown in the display no longer changes, you
should save the reference value by pressing the "OK" key or
the "Next" key.
The display now shows the adjacent screen:
Once calibration is complete, the offset of the electrode is
shown in the display.
Press the
OK
key to finish calibration.
ORP calibration errors
If the calibration was not able to be completed or the discrepancy is larger than 10%, the following causes are
possible:
The ORP electrode (combination electrode) is worn. The electrode service life is limited depending on the
water quality and its care.
You used the wrong buffer solution. It is imperative that 468mV is used. Calibration is not possible if other
buffer solutions are used.
The buffer solution is used up or contaminated. In this case, use a new buffer solution.
The electrode was connected to the wrong transmitter. The pH electrode must be connected to the white
transmitter.
The electrical connection between electrode and transmitter, or that between transmitter and controller, is
damaged.
7,20
800
721
675
D -2%
D +10%
pH
mV
Meas. Signal xxx,x mV
Buffer solution 468 mV
ok?
Offset xx,x mV
