Thermo Scientific Dionex ICS-5000 Operator's Manual page 233

3 seconds. Repeat two or three times. If the baseline does not improve,
check the other causes of baseline instability described in this section.
Do not block the end of the cell outlet tubing for longer than the
recommended 2 to 3 seconds. Doing so creates high backpressure,
which can break the pH-Ag/AgCl reference electrode glass membrane.
NOTE
To prevent air from becoming trapped in the cell in the future,
increase the backpressure on the cell by connecting backpres-
sure tubing to the cell outlet. The backpressure limit for the
ED cell is 690 kPa (100 psi). Do not exceed this limit.
•
(DC Amperometry and Integrated Amperometry modes) Frequent,
random spikes in the baseline
The pH-Ag/AgCl reference electrode diaphragm is plugged. First, try
regenerating the pH-Ag/AgCl reference electrode frit by soaking the
electrode in a solution of 1 M KCl plus 1 M HCl. If this does not
eliminate the spiking, replace the electrode (P/N 061879).
•
(DC Amperometry and Integrated Amperometry modes) Regular
baseline oscillation on high-sensitivity ranges
Reconnect the short length of titanium tubing to the cell inlet (see
Figure
•
(DC Amperometry and Integrated Amperometry modes) Dirty or
pitted conventional (nondisposable) working electrode
Polish the working electrode (see
disposable electrode, replace it.
•
(Integrated Amperometry mode) Regular baseline oscillations
1. Check the pump pressure plot to verify that the pump is working
properly.
2. Air bubbles may be trapped inside the cell. While wearing gloves and
eye protection, generate a slight temporary backpressure by putting
your finger over the end of the cell outlet tubing for 2 to 3 seconds.
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2-30).
8 • Troubleshooting
Section 9.28.4). If you are using a
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