50. absorption free standard, no matrix adjustment necessary
50. transmission measurements and extremely low background signal through the substrate thanks to a substrate thickness of only 200nm
50. mass depositions in the range of ng/mm2 (1 to 3 atom layers) allow for a quantification in this region without an extrapolation of higher values
50. mass loss in the range of 1 ng/mm2 (1 atom layer)
50. great variety of non-overlapping fluorescence lines makes an exact calibration curve with many values across a broad energy field possible
50. signal strength is adjustable through the film thickness and comparable for all elements (no signal saturation of the detector through a particularly strong line)
50. high uniformity and homogeneity (more than 1% across the whole sample surface)
50. usage for the adjustment of confocal µ-XRF mounts possible
50. great variety of available elements (standard version and customised configurations)

The reference samples contain seven different elements in a membrane with  characteristic fluorescence lines in the energy spectrum of ~2 keV to ~40 keV (peaks of comparable intensity), like shown in the picture.

The table shows the typical mass configuration (sample types RF7 and RF8, others available) and photon energies of the characteristic fluorescence lines. There is also a sample series with a mass configuration which is 10 times higher.