783620H / 1013 6. ANALYSIS METHODS
13) Determine the ending channel for N2 integration (denoted as N2
High
) as follows:
N2High = Pk
Start
+ L
14) N2 is then the summation of all counts from channel N2
Low
to N2
High
.
15) The final value B
3
is then simply the sum of N1 and N2.
6.9.1.3. Computing MDA
The MDA methods are computed from count rates, CR
mda
. To convert CR
mda
from counts to activity, a conversion factor MDA
conv
is used that contains detector efficiency, branching ratio, and activity correction factors.
(65)
where
ξ is defined in Eq. 146 and LT is the live time.
6.9.2. GammaVision MDA Methods
6.9.2.1. Method 1: Traditional ORTEC
(66)
where:
SENS
= Peak Cutoff value (%) on the Analysis tab or in the
.SDF
file
LT
= live time (sec)
NOTE
If the peak is rejected, the peak area is added to the background term B
1.
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