2 baseline wander and drift – INFICON 3000 Micro GC Gas Analyzer Operating Manual User Manual

Page 239

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3000 Micro GC Operating Manual

9.2.1.1.2 Baseline Wander and Drift

Baseline wander or drift is to be expected when a flow or temperature setting is
changed. With sufficient time, the problem should subside. The following cases
assume that sufficient stabilization time has elapsed.

Baseline is erratic; moves up and down (wander)

Potential column leak; check column connections

Change the sample conditioner filter

If there is a leak at the detector end of the column, the retention times will be
stable from run to run, but sensitivity will be reduced

If there is a leak at the inlet end, there will be reduced flow (lower linear velocity)
through the column, but there will be an increase in retention time and the
sensitivity will be reduced

Baseline moves steadily (drift) upscale or downscale during the run

This problem can be minimized by:

Conditioning the column

Operating at a lower temperature, but this prolongs the analysis

Substituting a chromatographically equivalent module

Wander and drift are often accompanied by noise. See

section 9.2.1.1.3

.

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