Multi 9420
Ion concentration
ba75964e04
04/2015
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6
Ion concentration
6.1
Measuring
6.1.1 Measuring
the ion concentration
The sensor connection and the USB-B (device) interface are gal-
vanically isolated. This facilitates interference-free measurements
also in the following cases:
Measurement in grounded test samples
Measurement with several sensors connected to one Multi 9420
in one test sample
Incorrect calibration of ion selective electrodes will result in incor-
rect measured values. Calibrate regularly before measuring.
For precise ISE measurements the temperature difference
between measurement and calibration should not be greater that
2 K. Therefore, adjust the temperature of the standard and
measuring solutions accordingly. If the temperature difference is
greater the
[TpErr]
warning appears in the measured value display.
1.
Connect the ISE combination electrode to the meter with the aid of an
ADA 94/IDS adapter.
The pH/ISE measuring window is displayed.
2.
In the measured value display, select the ISE measuring window with
<
> <
>
and
<M>
.
3.
If necessary, change the ion type in the
ISE setup
/
Ion type
menu.
4.
If necessary, measure the temperature of the test sample with a ther-
mometer.
5.
Calibrate or check the meter with the electrode.
While no valid calibration is available, e.g. in the delivery condition,
"Error" appears in the measured value display.
6.
Immerse the electrode in the test sample.
