Applied Biosystems Data Explorer 4 Series, User Manual

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Displaying PSD Data
Data Explorer
™
Software User’s Guide 8-7
8
If you are performing an internal standard calibration, the
software determines the constants as listed below:
Region of
segments included
in composite
spectrum
The composite spectrum is generated from portions of the
segment traces. The upper mass limit of the composite region
in each segment is determined by the PSD Mirror Ratio (R
n
)
with which the segment was acquired and the mass of the
precursor ion (m
p
) (Figure 8-3).
Figure 8-3 Portions of Segment Traces Included in the Composite Spectrum
PSD Internal
Standard Calibration
Constant Value Used
One-point
α
Calculated from standard mass
β
and
γ
0
Two-point or
three-point
α
and
β
Calculated from standard masses
γ
0
More than three-point
α, β, γ
Calculated from standard masses
Seg 1
Seg 2
Seg 3
Seg 4
R
1
x m
p
included in composite
R
2
x m
p
included in composite
R
3
x m
p
included in composite
(If first segment acquired
with PSD Mirror Ratio=1.0,
upper limit is
slightly higher than
precursor ion mass)