Device menu
10.2.2
Calibrating the pH measurement
The calibration of pH electrodes is carried out by measurements in buffer solutions with a
defined pH. The pH of the buffer solutions used are specified either by entering fixed
values in the calibration presets during calibration or recognised by the "automatic
detection buffer" during the calibration process. For the "automatic buffer recognition",
select a buffer set table in the calibration presets.
The buffer solutions used must be included in the set buffer set table here. Since the pH
measurement of liquids is temperature dependent, the temperature of the buffer solution
must be detected in order to compensate its influence on the measurement result.
This is done either by manual input or by using a temperature sensor.
To perform calibrations, you must be a registered user with the
corresponding user rights. See
10.2.2.1 Calibration presets
In the calibration presets, the calibration routines are released, which should be
accessible for the respective calibration. Non-approved calibration routines are not visible
in the calibration menu. More calibration presets are explained in the following table.
Parameter
Zero calibration Yes/No
Two-point
calibration
Three-point
calibration
Buffer set
selection
pH buffer 1
pH buffer 2
pH buffer 3
Temp
compensation:
10.2.2.2 Zero point calibration
With this calibration method of pH zero point of the measurement curve is determined.
The conductance is maintained.
As a reference, a buffer solution is required with a defined pH value.
417102269 Rev. 2-08.2020
Setting option
Yes/No
Yes/No
-2 to + 16pH
-2 to + 16pH
-2 to + 16pH
* No selection
or analogue inputs /
*IN4 temperature input 1
*IN5 temperature input 2
...
...
IN11 Universal input 2 uncomp.
* IN11 Universal input. 2 comp.
IN12 Universal input. 3 uncomp.
* IN12 Universal input. 3 comp.
(Please select only the
highlighted points)
Ä 10.1 'Login / logout' on page 108.
Explanation
Allow calibration type 'zero point'?
Calibration type: allow two-point
calibration?
Calibration type: allow three-point
calibration?
Automatic detection of buffer solutions -
this device is hidden
Presetting of the buffer solution to the
acidic range
Default of the buffer solution for the zero
point
Presetting of the buffer solution for the
alkaline range
Selecting the temperature input for the
automatic detection of the temperature
of the test/measurement solution during
calibration
(Only relevant if selected at
configuration / analogue inputs IN X
pH / redox / Manual compensation = no)
116
Default
Yes
Yes
Yes
No recognition
4,01
7,00
9,21
No selection