Empower Tip: Processing Methods

In this tip for Empower Chromatography Data System (CDS), we will continue our series on Processing Methods. In the last tip, we continued our series on creating Processing Methods and learned how to calculate signal-to-noise ratio using a specified segment from the blank injection, Tip 325.

In this tip, we learn how to calculate signal-to-noise ratio without the System Suitability Option. This would apply to a non-regulated environment.

Use the Noise and Drift tab in the Processing Method to have noise calculated. Using this tab, Empower can calculate Detector Noise, Detector Drift, and Peak-to-Peak Noise. As in previous tips, set the range over which Empower will calculate noise within the chromatogram of interest. The difference between Start Time and Stop Time must be greater than or equal to the specified segment width. The Segment Width is used to calculate average noise and drift values.

STEP 2:

Create a peak Custom Field to calculate signal-to-noise. In its simplest form, it would be height/noise. We do need to correct the unit difference between peak height (microvolts) versus peak-to-peak noise, which is in plot units, therefore we need to add the Scale to Microvolts field to the equation.

Signal-to-noise is calculated for our peaks and the peak-to-peak noise is found in the Chromatogram Result table in the Results window within Review.

It’s that easy!