Thermo Scientific Dionex UltiMate 3000 Series, Operating Instructions Manual

Page: 174 / 270

UltiMate 3000 Series:
NCS-3500RS and NCP-3200RS
Page 166 Operating Instructions
Problem Probable Cause Remedial Action
Pressure pulsation or
inconstant pressure
(Cont'd)
After a maintenance procedure
(replacement of pump head,
piston, or piston seal) the pistons
are not in the appropriate position
for normal operation.
Remove and reinstall the
pistons ( → pages 188
and 190).
Loading pump
The filter frit on the high-
pressure side of the pump is dirty.
Replace the filter frit
( → page 209).
Peak tailing Too large extra column volume. Use short capillaries with an
appropriate inner diameter
(Nano LC: 20 µm;
Cap LC: 50 µm;
Micro LC: 75µm).
There are poor capillary
connections.
Replace the capillaries.
Consider using Viper
capillaries.
Peak Broadening,
increased dead time
The inner diameter of the
capillary to the detector is too
large.
Use a capillary with an
appropriate inner diameter.
The filter frits on the solvent
supply lines are clogged.
Check the filter for
permeability. Replace the
filter frit if necessary
( → page 62).
With the NC pump, the
message 'Cannot regulate
flow' appears on the pump
display.
The capillaries are clogged or
there a poor capillary
connections.
Replace the capillaries.
Consider using Viper
capillaries.
The sample loop is clogged. Replace the sample loop
( → Autosampler manual ).
The column is overloaded or
contaminated.
Clean or replace the column.
The eluent has changed. Use fresh solvent.
A fused silica capillary with
poorly installed peek sleeve is
used.
Use an appropriate Viper
capillary instead.