GBS Elektronik MCA-527 - Manual (Page 67)

MCA527 Algorithm, Formulas
A MCA527 Algorithm, Formulas
This appendix lists the algorithms used by the MCA for the following functions:
●
Area, Area uncertainty
●
Centroid
●
FWHM
●
Smooth
●
Strip
●
Energy Calibration
The Area and the Area Uncertainty Function:
The area algorithm calculates the number of counts above the background in a ROI. The background area is
determined by averaging 4 points on both sides of the peak (the ROI limit points and 3 outer points) and linear
fit:
where
Spectrum
i
= the absolute number of counts in channels i
ROI
begin
= the ROI’s start channel
ROI
end
= the ROI’s stop channel
i = channel number
67
Background =
ROI
end
− ROI
begin
 1
8

∑
i =ROI
begin
− 3
ROI
begin
Spectrum
i

∑
i=ROI
end
ROI
end
 3
Spectrum
i

Integral = ∑
i= ROI
begin
ROI
end
Spectrum
i
Area Uncertainty=

Integral
 
∑
i= ROI
begin
− 3
ROI
begin
Spectrum
i

∑
i= ROI
end
ROI
end
 3
Spectrum
i

 ROI
end
− ROI
begin
 1
8
 2

Area=Integral−Background