Metrohm 844 UV/VIS Compact IC - Manual (Page 101)

4.3 Faults and malfunctions
844 UV/VIS Compact IC / Gebrauchsanweisung 8.844.1051
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4.3 Faults and malfunctions
4.3.1 Error messages
If any type of malfunction occurs during operation of the 844 UV/VIS
Compact IC, this is shown by error messages in the PC program, which
appear either in an error window or in the SYSTEM STATE window.
Follow the instructions listed in the Error window and close this
window with <OK> .
You will find further details of the error messages of the SYSTEM STATE
window, their possible causes and the procedure for rectifying them in
the Software Instructions for Use «IC Net 2.3» Section 4.5.
4.3.2 Malfunctions and their rectification
If difficulties appear with The 844 UV/VIS Compact IC during analyses,
their causes are best investigated in the order separating column →
high-pressure pump → eluent → connections. Several of The
malfunctions which may appear are listed in the following table with
details of possible causes and countermeasures.
Malfunction Cause Rectification
Baseline with high
noise level,
pulsation • Contaminated pump
valves
• Defective piston seals
• Clean the valves (see
Section 4.2.4)
• Replace the piston seals
(see Section 4.2.4)
Drift of the
baseline • Thermal equilibrium not
yet reached
• Leak in system
• Evaporation of organic
solvent in eluent
• Condition system with
heating switched on
• Check connections and
make leakproof
• Ensure better closure of
eluent supply vessel
Considerable
pressure drop • Leak in system • Check connections and
make leakproof
Considerable
pressure rise • Contamination of the
filter in the 6.2821.120
Filter unit PEEK
• Blockage of the preco-
lumn
• Change of column
packing by injection of
contaminated samples
• Replace the 6.2821.130
Filter (see Section 2.3.5)
• Change precolumn (see
Section 4.2.3)
• Regenerate column (see
Section 4.1.1) or replace
column (see Section 4.2.3)
Note:
Samples should always
be microfiltered.
Chromatograms
with poor
resolution, change
in the retention
times • Deterioration in
separation efficiency of
the IC column
• Regenerate column (see
Section 4.1.1) or replace
column