7
Troubleshooting
Detector-Related Problems
98
Accela PDA Detector Hardware Manual
Thermo Scientific
Random noisy
baseline.
Contaminated LightPipe flowcell.
Flush the flowcell with cleaning solvents (see
“Cleaning the LightPipe Flowcell”
).
Check for leaks.
Leak in sample inlet line.
Check all the fittings from the column outlet to
the flowcell inlet for leaks.
Bubble trapped in LightPipe flowcell.
Increase the flow rate until you remove the
bubble. Connect a backpressure device to the
flowcell outlet (check the pressure rating to avoid
rupturing the flowcell).
Leaking LightPipe flowcell.
Replace the flowcell.
Insufficient lamp warm-up.
Allow a 30 minute warm-up for normal
operation and a 1½ hour warm-up for maximum
sensitivity.
Aging or defective lamp.
Replace the lamp.
Ground loop problem between
integrator and detector.
Check the cable connections to the detector
output; do not ground at both ends of cable.
Dirty LightPipe flowcell or lamps.
Clean the dirty component.
Integrator input voltage does not match
detector output voltage.
Verify that the integrator is connected to the
appropriate Analog Output connections on the
back panel of the detector. (See
) Check the attenuation setting on
integrator.
Excessive baseline drift
.
Contaminated LightPipe flowcell.
Flush the flowcell with cleaning solvents as
described in
“Cleaning the LightPipe Flowcell”
. Check for leaks.
Mobile phase contamination.
Replace the mobile phase with fresh mobile
phase that is made with high-purity solvents.
Material bleeding from column.
Clean or replace the column.
Leaks in system or the LightPipe
flowcell.
Check all the fittings for leaks. Replace the
flowcell.
Tiny bubble trapped in LightPipe
flowcell.
Increase the flow rate until you remove the
bubble. Connect a backpressure device to the
flowcell outlet (check the backpressure rating to
avoid rupturing the flowcell).
Excessive temperature fluctuations.
Remove the system from drafts. Thermostatically
control the column temperature.
Table 5.
Detector-related problems (Sheet 2 of 4)
Symptom
Cause
Remedy