Assumption Of Bulk Matrix Corrections
In the meantime it should be noted that when an EPMA measurement is made near a boundary, most EPMA analysis software will generally report a concentration based on the assumption of a matrix correction based on all the intensities measured. Since this is not actually correct the utilization of these calculated intensities from Fanal requires some careful thought when performing off-line corrections of boundary fluorescent effects.
Note that the difference between the “Calc. Total Conc. %” (column H) and the “Meas. Total Conc. %” (column L) is that the “calculated” values are calculated using a matrix correction derived from the internally self-consistent k-ratios calculated by Fanal (which assume that the intensity emitted from material B is only affected by material B), while the “measured” values are the concentrations calculated using the Probe for EPMA matrix correction assuming that the measured intensities from both the beam incident material and the boundary material represent a homogeneous material. In other words the assumption of a bulk matrix correction.
Note that this is not actually the physical situation of a measurement near a boundary phase, however in order to correct the reported values from Probe for EPMA (which assumes a bulk correction for the time being), the use of the “measured” concentrations is necessary for an “apples to apples” comparison of the concentrations.