Dionex ICS-3000, Руководство оператора

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ICS-3000 Ion Chromatography System
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Doc. 065031-04 1/08
8.28.2 Cannot Set Amperometry Cell pH Readout to 7.0
The pH reading is displayed on the Chromeleon or Chromeleon Xpress
EC Detector Control panel.
•
Inaccurate calibration buffer
Use a pH meter to check the pH of the buffer.
•
Dry reference electrode
1. Soak the reference electrode in a solution containing 1 M KCl and
1 M HCl long
enough to restore the electrode potential to
<30 mV when compared to an unexposed Ag/AgCl reference
electrode
. To test the reference electrode potential, see “Using a
Digital Voltmeter to Determine Reference Potential Shift” on
page 226
.
2. Replace the reference electrode (see Section 9.24.4 ).
To prevent a reference electrode from drying out, make sure that
eluent is being pumped continuously through the cell. If the cell will
not be used for a short time (less than 2 days), disconnect the tubing
from the inlet and outlet fittings and install fitting plugs. For longer
shutdowns, remove the electrode from the cell and store it in its
storage bottle filled with saturated KCl solution. See
Section 4.1.2 for
detailed instructions.
8.28.3 Shift in Amperometry Cell pH Readout
The pH readout is considered to have shifted if it is 0.5 pH units or more
different from the value observed when the reference electrode was new.
•
Faulty reference electrode
1. Check the electrode by following the instructions in Section 8.28.6 .
2. Regenerate the electrode by soaking in a solution containing 1 M KCl
and 1 M HCl long
enough to restore the electrode potential to
<30 mV when compared to an unexposed Ag/AgCl reference
electrode
. To test the reference electrode potential, see “Using a
Digital Voltmeter to Determine Reference Potential Shift” on
page 226
.