Metrohm 940 Professional IC Vario ONE/Proep 2 - Manual (Page 89)

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6 Troubleshooting
940 Professional IC Vario ONE/Prep 2 (2.940.1120)
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Problem Cause Remedy
Injection valve – Valve
blocked. Have the valve cleaned (by a Metrohm service
technician).
The retention times
in the chromato-
gram have changed
unexpectedly. Separation column –
Diminished separating effi-
ciency. ￭ Regenerate the separation column (see
Chapter 5.15.4, page 78).
￭ Replace the separation column (see "Con-
necting the separation column", page 47).
The eluent contains gas
bubbles. ￭ Ensure that the connectors for the eluent
degasser are firmly connected .
￭ Deaerate the high-pressure pump (see Fig-
ure , page 42).
High-pressure pump –
Defective. Request Metrohm Service.
Peak areas are
lower than
expected. Sample – There is a leak in
the sample path. Find and fix the leak in the sample path.
Sample – The sample path
is blocked. Find and fix the blockage in the sample path.
Sample – The sample loop
is not (completely) filled. Adjust the transfer time for the sample (see
"Determining the transfer time", page 74).
Sample – There are gas
bubbles in the sample. Use the sample degasser .
The peristaltic pump
is pumping too little. Peristaltic pump – Contact
pressure too weak. Correctly set the contact pressure .
Peristaltic pump – Filter
blocked. Replace the filter (see "Replacing the filter",
page 77).
Peristaltic pump – Pump
tubing defective. Replace the pump tubing .
Data of the separa-
tion column cannot
be read. Column chip contamina-
ted. Clean the contact surfaces of the column chip
with alcohol.
Column chip is defective. 1. Save column configuration in MagIC Net™.
2. Notify Metrohm Service.
Individual peaks are
greater than
expected. Sample – Sample carry-
over from the previous
measurement. Check the rinsing time (see "Checking the rins-
ing time", page 75).