Integrated Intensity Options

EPMA Probe

Integrated Intensity Options

For standard and unknown samples, if the element is acquired on a tunable spectrometer, the program offers an option acquire the integrated intensity over the peak instead of simply the peak intensity. If this option is checked, the program will start scanning at the low or high off-peak limit using the Initial Step Size specified and scan to the other off-peak limit.

 

The actual step size is modified based on the acquired intensity so that as the intensity increases, the step size decreases to the Minimum Step Size specified. This improves statistics where it is needed the most. The default step size is 1/80th of the off-peak range and the default minimum step size is 1/200th of the off-peak range.

 

The program accumulates the intensities over the off-peak range and this is stored as the on-peak data. The off-peak intensities are also measured normally and the integrated background is calculated based on the background type selected and the off-peak intensities. The integrated peak intensity itself is calculated using a cubic spline fit to the data. All off-peak options may be used with the integrated intensity option. The reported integrated intensities are in units of counts per second times spectrometer units divided by the spectrometer unit range (cps per second per spectrometer unit).

 

If an element is acquired using the integrated intensity option, the standard intensities for that element must also be acquired using the integrated option and preferably using the same off-peak range. See the Run | Display Integrated Intensities menu for a graphical display of the integrated intensity data and cubic spline fitting.