Problem Cause Action
There are differences in internal diameter
b
etween the tubing on the column, the
tubing from the pump, or anywhere else in
the system.
Change tubing to the same
diameter.
The pressure gauge is showing faulty
v
alues.
Change or calibrate the pres-
sure gauge.
Column leakage The end-piece and/or flange is not prop-
e
rly positioned with respect to the tube.
Disassemble and re-assemble
the column.
The solvents used are not compatible with
t
he O-rings and gaskets.
Check solvent, see Section 8.2
Chemical resistance, on page
132.
The tubing is not compatible with all the
s
olvents.
Change solvent.
The connectors have not the same dimen-
s
ions.
Change connectors.
Air leaks into the column from the suction
s
ide of the pump.
Check that the connections to
and from the pump are correct
and tightened.
The torque is not correcton the rods or the
f
lange.
Check that the correct torque
specification has been used
during column assembly.
Chromatogram not
a
s expected
The linear velocity is not as expected. Check sample.
Back-mixing has occurred anywhere in the
c
olumn set-up.
Check connections.
The sample could have passed through an
a
ir trap.
Check connections or test
method.
The adapter is not correctly positioned in
c
lose contact with the bed.
• M
ove the adaptor down 5
mm into the bed.
• Disassemble and assemble
the column.
The column packing has not been
c
hecked.
Check the column packing.
The column has not been correctly equili-
b
rated.
Equilibrate the column.
Old sample mixed with new. Check sample and sample
h
andling.
7 Troubleshooting
122
BPG Columns Operating Instructions 29193223 AB
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