Empower Tip: Review Window and the Processing Method

Just about everyone wants to calculate signal-to-noise ratio and Empower Software can make the calculation in several different ways. Let’s begin by looking at the simple calculation of peak height divided by noise. (Part 1)

Bring raw data (Channels, Injections or Sample Set) into Review and open the processing method. Click the Processing Parameters tool.

Click the Suitability tab and check the box that says Calculate Suitability Results. Enter the Void Volume Time, an estimate is fine.

Select how you want noise calculated from the Noise Value for s/n drop-down list. Peak to Peak Noise is a popular choice.

4. Select where in the chromatogram you want noise calculated by clicking the Noise and Drift tab. Click Yes to the message that appears.

Select Calculate Detector Noise and Drift.

Enter a time region in the chromatogram which is free of peaks. This time region must be equal to or greater than the Segment Width and must contain at least 60 data points. The Segment Width is used for calculating average noise and drift values and it must contain at least 30 data points.

Return to the Main Window and click Integrate followed by either Calibrate or Quantitate.

Signal to Noise is a hidden field by default so let’s add it to our Peaks table. Right-click on the Peaks table and select Table Properties.

On the Columns tab, find s/n and remove the check mark to make it visible in the table. Click OK.

The signal-to-noise ratio is displayed for every integrated peak.

To keep the s/n field in the peaks table, select Save Preferences from the File menu.

Finally, save all changes to the Processing Method.

It’s that easy!