7
Troubleshooting
Detector-Related Problems
Thermo Scientific
Surveyor PDA Plus Detector Hardware Manual
99
3. Excessive baseline
drift
.
a. Flow cell contaminated.
a. Flush the flow cell with cleaning solvents
as described in
. Check for leaks.
b. Mobile phase contamination.
b. Replace with fresh mobile phase made
with high-purity solvents.
c.
Material bleeding from column.
c.
Clean or replace the column.
d. Leaks in system, or flow cell.
d. Check all of the fittings for leaks.
Replace the flow cell.
e.
Tiny bubble trapped in flow cell.
e.
Increase the flow rate until the bubble is
removed. Connect a backpressure device
to the flow cell outlet (check the
backpressure rating to avoid rupturing
flow cell).
f.
Large temperature fluctuations.
f.
Remove the system from drafts.
Thermostatically control the column
temperature.
4. No peaks, or peaks
much smaller than
expected.
a. Incorrect wavelength setting.
a. Check the wavelength setting. Make
sure the correct file is selected.
b. Lamp not on, or defective.
b. Make sure the lamp is lit. Run detector’s
diagnostic tests to check the lamps.
Replace the lamps if necessary.
c.
Integrator input voltage does not match
detector output voltage.
c.
Verify that the integrator is connected to
the appropriate Analog Output
connections on the detector. (See
attenuation setting on integrator.
d. Insufficient sample reaching the
detector.
d. Check the entire chromatographic
system for leaks. Verify the sample
injection volume.
5. Broad, tailing
peaks.
a. Rise time is too large (too slow).
a. Lower the rise time selection.
b. Poor connection at flow cell inlet.
b. Check the end of inlet tubing for a
clean, flat surface free of obstructions.
Table 3.
Troubleshooting detector-related problems (Sheet 3 of 4)
Symptom
Cause
Remedy
