Operation
4.5.3.2
Calibration with standards, redox
4.5.3.3
Manual, indirect calibration
4.5.3.4
"Calibration data" introduction
26
The metallic electrodes do not suffer significant modifications in time. For this reason, it is
not very common to calibrate them.
Nevertheless, some deviations can produce after long use of the electrode due to
contamination of the metallic surface or contamination of the reference electrolyte. To
compensate this deviations is recommended calibration using redox standard solution 220
mV at 25 °C.
See
Calibration procedure, Page 25
Note: During calibration with buffers, the relays assigned to the corresponding channel stay
deactivated. The 4-20 mA outputs (register) are in Hold (21 mA or last value).
* Channel 2 and 3 activated. This message appears when Individual Hold (sensors installed in
different places) is programmed.
The configuration of set Hold means relays deactivation of all channels during calibration with
standards of any of the sensors.
Readjustment of the measured value. It can be done for any of the measuring channels.
For this purpose, previously the pH or mV value of the sample should have been
measured using perfectly calibrated instrument. During pH readjustment, the instrument
carries out one point calibration, it means compensates only the asymmetry potential
maintaining the previous slope.
1. From the main menu select
2. Select the channel to calibrate and confirm.
3. Select
MANUAL CALIBRATION
Note: The manual calibration do not provoke any change in relays and 4-20 mA output. The
cleaning relay is deactivated during the manual calibration.
4. Set the pH value using the direction keys.
5. Accept calibration.
This option is very useful when calibration with buffers can not be performed in the sensor
installation place. A sensor calibration is performed in a laboratory and afterwards the
obtained data are introduced in this type of calibration.
1. From the main menu select
2. Select the channel to calibrate and confirm.
3. Select
CALIBRATION DATA
Note: The calibration data introduction do not provoke any change in relays and 4-20 mA output.
The cleaning relay is deactivated during the data introduction.
4. Set the values for calibration data using the keypad.
5. Press
to accept calibration.
CONTINUE
Note: Once the introduced data are accepted, MultiMeter 44 eliminates the last calibration with
buffer solution.
Theoretical calibration
Introduction of the data corresponding to a theoretical calibration:
Asymmetry potential: 0 mV
•
. Confirm.
CALIBRATE
and confirm.
Confirm.
CALIBRATE.
and confirm.