DSPEC 50
®
and DSPEC 502
®
Digital Gamma-Ray Spectrometer User’s Manual
932502G / 0618
be expressed as ± with a 1-sigma confidence limit, where
N
is the corrected
spectral data and
V
is the variance (error) spectral data.
The live time is set to the real time within the analysis engine during the analysis of ZDT
spectra.
A
CORR_ERR
spectrum is analyzed
8
as a regular spectrum most of the time, with a few
exceptions as listed below.
!
To calculate the peak area uncertainty, the error spectrum is used. If the peak limits are
from
L
and
H
channels, then the background variance is calculated as:
where:
B
1
= sum of background counts for the channels adjacent to the peak start (low-
energy) channel
L
B
2
= sum of background counts for the channels adjacent to the peak end (high-
energy) channel
H
n
1
= the number of low background points (
n
1
= 1, 3, or 5) used
n
2
= the number of high background points (
n
2
= 1, 3, or 5) used
The peak area uncertainty is calculated from:
where G is the sum of counts, from the error spectrum, from channels
L
to
H
.
!
In our WAN and ISOWAN analysis engines, the peak-fitting routine fits all the library
peaks as singlets to calculate the peak centroid, peak start and end channels, and peak
background. A linear background under the peak is assumed during the peak fitting
process.
8
Using our gamma-ray spectrum analysis software such as GammaVision
®
or ISOTOPIC.
12
