Comparing the results from several chromatograms

Clarity provides two complementary ways to compare results from several chromatograms:

• Overlay mode, which displays multiple chromatograms simultaneously in a single graph.
• Browse Through Chromatograms, which allows reviewing them one by one in sequence.

Both approaches can be used to evaluate differences between chromatograms, verify results, and prepare data for reporting or further processing.

Comparing chromatograms using Overlay mode

The default maximum number of chromatograms that can be open in Overlay mode is 20. If your workflow requires comparing a larger number of chromatograms (for example, when producing a summary report), this limit can be changed in the User Options dialog, accessible from the Instrument window by using Setting - User Options....

To view chromatograms in Overlay mode, follow these steps:

1. Open the chromatograms using File - Open Chromatogram....
2. In Open Chromatogram dialog select desired chromatograms and click Open in Overlay.
3. Click on the Summary tab in the lower part of the window to display the Summary Table. In the rows you can see chromatograms and signals with measured values and in the columns there are identified peaks from all calibrated chromatograms.

Caution:

Summary Table is based on calibration, meaning only calibrated peaks will be present in it.

4. Right click on the Summary Tableto access options for adjusting its layout or content, including the Inverted view, which switches the table from a horizontal format to a vertical one for easier inspection of individual results.
5. To see all signals, select the Show All Signals checkbox in the Summary Table Options dialog accessible from the pop-up menu of the Summary Table. By default, only signals containing calibrated peaks are visible in the Summary Table.

Comparing chromatograms by browsing them sequentially

In addition to Overlay mode, Clarity also allows reviewing multiple chromatograms one after another using the Browse Through Chromatograms function. This method is useful when you want to visually inspect each chromatogram individually, especially when working with large batches.

To use this feature, the Overlay mode must be disabled.

To browse chromatograms, follow these steps:

1. You can browse the chromatogram by using File - Browse Through Chromatograms or by using the navigation controls in the toolbar. By default, Clarity browses the folder of the currently open chromatogram.



2. In the Open Chromatogram dialog, select the chromatograms you want to review. You can also filter the list by typing simple wildcard patterns (*, ?).

Caution:

Using %variables when creating chromatogram file names is strongly recommended, as it ensures that useful information, such as sample name, injection number, or date, is included automatically. This makes it much easier to search, sort, or filter chromatograms when browsing through them.

3. When you have the desired files selected, you can open them by using Browse Selected Chromatograms.