Drifting Baseline - Thermo Scientific Dionex ICS Series Operator's Manual

Dionex PDA Operator's Manual
4.6

Drifting Baseline

•
Fluctuations in ambient temperature
Make sure the Dionex PDA installation site temperature remains consistent.
Allow at least 6 cm (2.4 in) of clearance behind the Dionex PDA for
ventilation.
Check that the flow cell inlet tubing is routed through the heat exchanger (see
Figure 2-5) and is correctly connected to the inside front panel (see
Figure 5-2). Check that solvent flow is directed to the cell inlet and out the
cell outlet.
Select the active reference mode by entering a reference wavelength (see
page 47).
•
Front cover, lamp cover, or flow cell cover is missing
Optical components are sensitive to temperature and light. Do not operate the
Dionex PDA unless the front cover, lamp cover, and flow cell cover are in
place.
•
Flow cell heat exchanger not in place
Check that the flow cell inlet tubing is threaded through the tubing guide on
the lamp cover and secured in place with the tubing bracket (see
•
Lamp not stabilized or burned in
The lamps usually require 20 to 30 minutes to stabilize. For sensitive
applications work or for detector validation, allow at least 2 hours for the
lamps to stabilize. After installing a new lamp, allow from 8 to 24 hours for
the lamp to stabilize.
After changing mobile phases, allow 20 to 30 column volumes for the system
to stabilize.
•
Leaking flow cell
Tighten fittings. Also, check that the backpressure on the cell does not exceed
the specification (see
If the cell continues to leak, replace it (see
78
Section A.5).
Section 5.6).
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Figure 5-1).