User`s guide

Chapter 6 Acquiring Mass Spectra
6-32 PerSeptive Biosystems
6
6.5.3 Calculating Signal-to-RMS Noise Ratio
Overview A signal-to-RMS noise ratio is typically used to describe how
well a mass of interest in a spectrum is distinguished from
background chemical and electronic noise.
The Control Panel software measures the signal-to-noise ratio
in a user-defined region of a mass spectrum.
Calculating
signal-to-RMS
noise ratio
To calculate a signal-to-RMS noise ratio:
1. When acquisition is complete, select the Current
spectrum of interest.
2. From the Tools menu, select Signal-to-Noise Calculator.
3. In the Signal to Noise Calculator dialog box (Figure 6-14),
set the Baseline Region by doing one of the following:
• Type in From and To values
• In the Spectrum window, right-click-drag over the
baseline area you want to use in calculating
signal-to-noise ratio. For accurate results, specify a
flat (non-rising) region of baseline that does not
include peaks.
Figure 6-14 Signal to Noise Calculator