ZAF

EPMA Xtreme Probe

ZAF

A method for the matrix correction of emitted (as opposed to generated) x-rays  from a sample. The method calculates the effects of atomic number (Z), absorption (A) and characteristic (and sometimes continuum) fluorescence (F) separately, hence the name ZAF. To put all of this in perspective, here is the complete ZAF correction expression for x-ray intensities solved for the concentration of an unknown concentration :

 

where :    is the unknown k-ratio and

 

                 is the ZAF correction factor of the unknown

 

                   is the unknown intensity for element A at λ

                   is the standard intensity for element A at λ

                               is the concentration of the element in the standard

                 is the ZAF correction for the element in the standard

Because the ZAF correction factor for the unknown is exactly that : unknown, the calculation requires a iterative solution. See also Phi-Rho-Z.