Drift

A signal change over time, e.g., caused by a temperature change in the laboratory, gradient elution, or detector drift, is referred to as drift.

To show the drift in Chromeleon: Add a new report variable in the report or in the Printer Layout. Select Insert Chromeleon Report Variable or Insert Column on the context menu to open the appropriate dialog box. In the dialog box, select Chromatogram from the Categories list and Signal Value from the Variables list.

Click Parameter to open the Parameter Input for 'Signal Value' dialog box and select Drift. Select the Restrict Range from check box and determine the range for which the drift is calculated.

To compute the drift, a regression line is drawn through all data points. The slope of the regression line is the calculated drift. Therefore, to compute the drift, always select a baseline range in which no peaks occur.

 Note: 

Unless the step is equidistant, all data points are weighted with their corresponding steps to determine the regression line.

The drift is always indicated in [Signal]/min.