The Detector Efficiency Question with EDS

The knowledge about EDS detector efficiency is a core question with standardless quantification of measured spectra, to convert the measured X-ray counts into the values which were really emitted from specimen. Quantmodels for sample composition calculations always start with the input of emitted X-rays, not with the measured X-rays. The detector influence cancels out if measured P/B are used or when net-counts of a known standard are measured with the same detector. But even if the standards were measured with another detector (or even with another type) it matters much to know the real efficiency with each detector.