Thermo Scientific Accela UV/Vis Plus, Hardware Manual

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4
Troubleshooting
Detector-Related Problems
Thermo Scientific Accela UV/Vis Detector Hardware Manual 59
Random noisy baseline Contaminated flow cell Flush the flow cell with cleaning solvents. See
“Cleaning the LightPipe Flow Cell” on page 45 .
Check for leaks.
Leak in sample inlet line Check all of the fittings for leaks, from the
column outlet to the flow cell inlet.
Bubble trapped in flow cell Increase the flow rate until the bubble is
removed. Connect a backpressure device to the
flow cell (check pressure rating to avoid
rupturing the flow cell).
Leaking flow cell Replace the flow cell.
Insufficient lamp warm-up Allow a 30 minute warm-up for normal
operation and a 1.5 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 the cable.
Dirty flow cell or lamps Clean the dirty component. See “Cleaning the
LightPipe Flow Cell” on page 45 .
Integrator input and output voltage not
matching Verify that the integrator is connected to the
appropriate analog output connections on the
back panel of the detector. See
“Connecting the
Analog Outputs” on page 34 .
Check the attenuation setting on the integrator.
Excessive baseline drift Contaminated flow cell Flush the flow cell with cleaning solvents. See
“Cleaning the LightPipe Flow Cell” on page 45 .
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 flow cell Check all of the fittings for leaks. Replace the
flow cell.
Tiny bubble trapped in the flow cell Increase the flow rate until the bubble is
removed. Connect a backpressure device to the
flow cell outlet (check backpressure rating to
avoid rupturing flow cell).
Excessive temperature fluctuations Remove the system from drafts. Thermostatically
control the column temperature.
Table 6. Detector-related problems (Sheet 2 of 3)
Symptom Cause Remedy