Analysis of stratified samples
Electron probe X-ray microanalysis - Applications and developments

While conventional quantification procedures require a homogeneous sample in the analysis volume, f ( ρz ) models make it possible to analyze stratified samples, i.e. a succession of thin layers of constant thickness, with a total thickness of no more than a few microns.

For a layer buried between depths ρz _i and ρz _i+1 containing element A, we can, by definition of f (ρz ), write that the characteristic emergent intensity of the element under consideration coming from layer i is equal to :