Applied Biosystems Data Explorer 4 Series, User Manual

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Using the Signal-to-Noise Ratio Calculator
Data Explorer
™
Software User’s Guide 6-23
6
6.4 Using the Signal-to-Noise Ratio
Calculator
Description
A signal-to-noise ratio is typically used to describe how well a
peak of interest in a spectrum or chromatogram is
distinguished from background noise.
The Data Explorer software provides two signal-to-noise ratio
methods that calculate signal-to-RMS noise (electronic and
chemical):
• Auto—You specify the peak for calculation and the
software automatically calculates the average noise
across the spectrum.
• Manual—You specify the peak and the baseline region
for calculation. For accurate results, this method requires
a flat (non-rising) baseline that does not include peaks.
The manual method is useful when evaluating a narrow
region around a peak to determine the relative
significance of a peak.
Calculating
signal-to-noise
ratio
To calculate a signal-to-noise ratio:
1. Click the Spectrum window to activate it.
2. From the Tools menu, select S/N Calculator.
The Signal-to-Noise Calculator dialog box (Figure 6-14)
is displayed.
Figure 6-14 Signal-to-Noise Dialog Box