Waters Alliance e2695 Operator's Manual page 173

Table 8–9: Chromatography troubleshooting (continued)
Symptom
Baseline noise cycling, short
term
(30 to 60 sec)
Baseline noise cycling,
long-term (approximately
10 min to 1 hour)
Baseline noise, random
Possible cause
Flow fluctuating
Solvent not well mixed (short-
or long-term cycling)
Radio frequency noise (short-
or long-term cycling)
Ambient temperature
fluctuations
Faulty Integrator or recorder
Solvent time in the degasser is
not sufficient to remove
UV-absorbing gas (e.g., O
Air in detector
Solvents not properly
degassed
Bubble detected
Solvents contaminated
Column contaminated
Dirty flow cell
Analog output cable not
properly connected between
the separations module and
data system, recorder, or
integrator
System improperly grounded
Incorrect voltage setting:
• Recorder
• Analog-to-digital converter
Unit not cooling properly
Radio frequency noise
Defective detector
February 27, 2018, 715003794 Rev. C
Page 173
Corrective action
Stabilize flow by checking for
leaks and for proper
degassing (see "Erratic
retention times" symptom).
Stir solvent.
Eliminate interference.
Stabilize ambient temperature.
Evaluate integrator or recorder
performance.
Maintain < 1 mL/min.
maximum flow rate.
)
2
Purge detector to remove air.
Degas solvents.
Reprime the solvent
management system. Remove
and vacuum filter solvents.
Use fresh solvent.
Clean/replace column.
Clean flow cell.
Properly connect cable.
Plug into outlet on different
electrical circuit.
Use power conditioner.
Adjust voltage setting.
Operate unit with covers in
place. Confirm prescribed
clearance at the rear of device.
Perform the Defrost Sample
Procedure (see "Defrost
sample heater/cooler function"
on page 166).
Eliminate interference.
Troubleshoot detector.