Overlay

An Overlay is a chromatogram that is displayed in addition to the open chromatogram, i.e., overlaying the open chromatogram. Overlays are often used to compare chromatograms. To do so, several chromatograms can be overlaid at several positions in Chromeleon:

Control Panel

You can overlay chromatograms during data acquisition. Open a Control Panel and select Chromatogram Overlay on the context menu of the online signal plot. In addition to the currently recorded channels, a previously recorded chromatogram is displayed.

QNT Editor and Report

Select Add Overlay on the File menu in either the Report or the QNT Editor (see Data Representation and Reprocessing  The QNT Editor) to overlay chromatograms after data acquisition.

Printer Layout

To plot overlaid chromatograms, select Chromatogram Properties on the context menu of a chromatogram (in the Printer Layout) and make the corresponding settings on the Overlay tab page.

In each plot, you can use a processed sample of the current sequence or of any other sequence as the reference chromatogram.

Also, refer to How to …: Working with Chromatograms  Comparing Chromatograms.