Ise Calibration - wtw inoLab pH/ION Level 2 Operating Manual

Why calibrate?
When to calibrate?
ConCal
AutoRead
TP display

4.5 ISE Calibration

Ion sensitive electrodes age and are temperature depen-
dent. This changes the slope. As a result, an inexact mea-
sured value is displayed. Calibration determines the current
values of the slope of the electrode and stores it in the instru-
ment.
Thus, you should calibrate before each measurement (if
possible), and at regular intervals.
Note
For calibration, use tempered standard solutions with a tem-
perature that differs by maximum
ture of the test sample.
l Before each ISE measurement if possible
l After connecting another electrode
l When the sensor symbol flashes after a voltage interrup-
tion, e.g. battery change.
is the conventional two-point calibration or three-point cali-
bration with 2 or 3 freely selectable buffer solutions. The
concentration of the calibration standards depends on the
concentration that is expected to be measured.
In calibration, the AutoRead function is automatically acti-
vated.
The current AutoRead measurement (with acceptance of
the current value) can be terminated at any time by
g
pressing .
If you use a temperature probe, a flashing TP display indi-
cates that the temperature difference between the test sam-
ple and the standard solutions is too high (
Operation
2 °C from the tempera-
±
2 °C).
±
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