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3.3 Specific Ion Calibration
1.
Plug the Ion Selective Electrode into the
Probe 1
,
Probe 2
or
Probe 3
socket.
If a separate Reference Electrode is being used, plus this into the matching 4mm
Ref 1
,
Ref 2
or
Ref 3
socket provided.
Plug the Temperature sensor into the
Temp.
socket.
2.
Switch the meter on.
3.
Select and set up Ion mode, as detailed in section 3.1.
Set up the Primary and Secondary Specific Ion standards, as detailed in section 3.2.
For the purposes of this handbook, the
900-I3
has been set up for 100ppM as the Primary
Standard and 10.0ppM as the Secondary Standard.
4.
Ensure that temperature has already been calibrated (section 7.1) or manually set (section 7.4).
NOTE
: A “
∗∗
” in place of the decimal point in the temperature readout indicates that
temperature is not calibrated.
5.
Remove the wetting caps from the Ion Selective and Reference electrodes, if fitted.
Rinse the Ion Selective, Reference and Temperature sensors in distilled water and blot dry.
Primary Calibration
6.
Place the Ion Selective, Reference and Temperature sensors into the Primary Standard.
Ensure that the Ion Selective Electrode sensing surface and the reference electrode’s reference
junction are both covered, as per the diagram below.
Add any Ionic Strength Adjusting Buffer (ISAB) that may be required (see the Ion Selective
Electrode’s handbook).
A magnetic stirrer providing constant, gentle stirring generally improves stability.
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