Waters 515 HPLC - Page 94

4-36 Maintaining and Troubleshooting the Waters 515 Pump
Baseline noise
cycling, short-term
(30 sec to 60 sec)
Fluctuating flow rate Sparge or degas eluent. Try
repriming the pump(s). If
necessary, check flow
accuracy of the pump(s).
Inadequate eluent
blending
Install a mixer as shown in
the figure “Three-pump,
high-pressure gradient
configuration with optional
mixer” on page 2-12.
AC power source (short-
or long- term cycling)
Disconnect other instruments
on the power line; try a
different wall outlet; have line
voltage checked; use power
conditioner.
Radio frequency noise
(short- or long-term
cycling)
Eliminate interference.
Baseline noise
cycling,
long-term
(approximately
1hour)
Ambient temperature
fluctuations
Stabilize ambient
temperature.
Integrator or recorder
faulty
Check integrator or recorder
for excessive baseline noise.
Identifying chromatographic problems (Continued)
Symptom Possible cause Corrective action