Metrohm 949 - Automatic Calibration

5.5 pH parameters
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P1.9 pH temperature offset
All devices of the 949 pH Meter type are precalibrated for a correct temp-
erature measurement. If the temperature sensor malfunctions, there may
be a difference between the measured temperature and the actual temp-
erature.
P1.9 is used to perform an offset alignment of the temperature of up to
±5 °C:
1
Use the and buttons to correct the temperature offset value.
2
Confirm the setting with the button.
5.5.3 Automatic calibration
Automatic calibration is depicted using 3-point calibration with Metrohm
buffers (7.00/4.00/9.00) as an example.
Calibrating the 1st point
1
In measuring mode in the area, press the button to access
calibration mode.
The 1ST POINT PH 7.00 message appears on the display. The mes-
sage means that the 949 pH Meter requires the neutral value as the
1st calibration point.
2
Remove the vessel from the electrode.
3
Screw open the closure of the filler opening on the electrode.
4
Rinse the electrode with distilled water.
5
Immerse the electrode in the pH 7.00 buffer solution.
The WAIT FOR STABILITY message appears on the display and the
symbol flashes.
6
As soon as buffer 7.00 is detected and the symbol appears, press
the button.