Peak area and area uncertainty calculation
From HyperLab version 2005, a fine-tuned peak area uncertainty calculation method is applied, which is described in this section.
Objective function for fitting
During the spectrum fitting, we try to fit a sum of peak, skew and background functions to the measured counts. The standard
Chi-Squared used as a merit function for the goodness of fit:
where
| Countj
| Measured count in the j'th channel of the region
|
|
| var(Countj)
| Variance of the measured count at j
|
|
| Yj
| Sum of peak and background functions at j
|
|
| n
| Number of channels in the region
|
Calculation of the peak area
If the fit reaches a minimum, peak area is calculated from the actual values of the fitted and/or fixed parameters:
where
| GAmpl
| Gaussian Amplitude
|
|
| GWidth
| Gaussian width (FWHM / 1.6651)
|
|
| LSAmpl
| Left Skew Amplitude
|
|
| LSSlope
| Left Skew Slope
|
|
| RSAmpl
| Right Skew Amplitude
|
|
| RSSlope
| Right Skew Slope
|
