Calibration Of Orp Electrode - Hach LANGE si629 P Bedienungsanleitung

4. Operation

4.7. Calibration of ORP electrode

The metallic electrodes do not show significant drift of poten-
tial, for this reason usually they are not calibrated. However,
some deviations of potential may occur after continued use
of the electrode due to alterations of the metallic surface
or reference system contamination. For the compensation
of these deviations, we recommends the calibration using
redox standard of 220 mV (25ºC).
1. Selection of the temperature of the standard.
2. Calibration with standard 220 mV.
If there is an anomaly during the calibration, there will be
an error message.
Notes: During calibration the instrument is in Hold state:
• Limit and cleaning contact relays are opened.
(Alarm OFF).
• Current output is frozen at the value programmed in Hold.
To quit the Hold state it is necessary to return to measure.
The Current output 4 to 20 and the Relays will activate in 10 sec.
For practical reasons, during CALIBRATION, we recomends to
introduce the buffer temperature manually despite the ATC probe
(Pt 1000/Pt 100) is connected.
When the required adjustment for performing the calibration is
more than 60 mV, there will be the following error message.
Si629 P allows performing manual readjustment of mV, follow
instructions at page 23.
si629 P_HACH_LANGE_Ed.0510.indd ANG:21 si629 P_HACH_LANGE_Ed.0510.indd ANG:21
M E A S U R I N G
3 6 5 M V
Introduce the
CODE 000
code 100
CALIBRATION
Introduce the
INSERT BUFFER
standard's
220 MV 25°C
temperature with
the keys
CALIBRATING
228 MV 20°C
Automatic
change of the
display. It occurs
once the reading
ADJUST
is stable
8 MV
Press
accept
calibration
CALIBRATION OK
mV adjust
> 60 mV
to
21
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