HP Data Explorer 4 Series - Manual (Page 211)

Manual Calibration
Data Explorer ™ Software User’s Guide 5-7
5
5.3.2 Manually Calibrating
This section describes:
• Before calibrating Voyager data
• Manually calibrating a single spectrum
• Applying new constants to the data file
• Exporting calibration constants (.CAL file)
• Applying new constants to additional files
Before calibrating
Voyager data
Before you calibrate Voyager data, do the following to improve
mass accuracy:
• Baseline correct—The Centroid% peak detection value
is derived from a percentage of the peak height, which is
measured from 0 (not from the local baseline). For
information, see Section 5.8.2, Using Baseline
Correction.
• Noise filter or use default smoothing—Use the method
appropriate for your data to remove noise spikes. For
more information, see Section 5.7, Noise
Filtering/Smoothing.
It is critical to perform both these functions, which affect the
peak centroid, before calibration. It is also good practice to
perform the same processing functions on calibrants and
unknowns.
NOTE: If you are calibrating Mariner data, baseline
correction and noise filtering or smoothing are not
recommended before calibrating. Due to the shorter flight
times and fewer data points associated with Mariner data,
these functions may affect peak shape, which in turn affect
mass accuracy.