Integral linearity, multichannel

In view of the resolution characteristics of an ED detector, spectral overlap interferences are much more common in ED-XRE than WD-XRF and require a more comprehensive correction procedure than the simple line ratio method often used in the latter technique. However, advantage can be taken of the digital form in which ED spectral data are accumulated in the multichannel analyzer, which offers information about peakshapes as well as intensity. For simple ED spectra, it may be possible to define a series of windows covering each fluorescence peak of interest (the region-of-interest approach). Peak intensities can then be determined by chaimel integration and a background correction applied by linear interpolation between the lowest and the highest channel of the window. For complex spectra, a more sophisticated approach is required, of which two have found widespread use. 

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