Bio-Rad ChromLab™ Software - Manual (Page 252)

B | Troubleshooting the Instrument
250 | NGC Chromatography Systems and ChromLab Software
The backpressure
drops to zero or is
much lower than
expected (continued). The check valves might need to
be cleaned or replaced.  Perform CIP to clean the
check valves.
See the NGC Chromatography
Systems and ChromLab
Software User Guide for more
information.
 Replace check valves.
See Disassembling the Pumps
on page 159 .
No pressure (psi)
reading, or the psi
value always reads
zero. The pumps might not be running. Verify that the pumps are
running, and that the inlet lines
are primed and not pulled out of
the buffer reservoirs. Check the
fittings for leaks.
The inlet lines are not primed, or
there is a problem with the buffer
flow. In ChromLab, open the Sample
Inject Valve dialog box and
verify that the buffer flow is
going to the column and not to
waste.
The “zero pump pressure”
calibration routine might have
been used while the system was
under pressure. Stop the system pumps and
disconnect the line from the
pump to the inject valve so that
the pressure transducer in the
pump module is definitely at
zero psi.
Note: Recalibrate after
stopping the pumps. In
ChromLab, select Tools >
Calibrate > Pump Flow
Rate. Complete the
calibration steps in the
dialog box.
Symptom Possible Cause Possible Solution