Matching an unknown spectrum to the potential library candidates is based on the Chi-squared goodness of fit statistical approach comparing either concentrations or spectra lines directly. The match sensitivity is adjustable, providing complete control over match results for the desired degree of confidence.
The potential matching spectra are overlaid on the original spectrum. The match percentage measures how similar or dissimilar the spectra are and visually represents the differences.
The EDAX Smart Materials and Minerals Library option provides 150 entries of common metal standard alloys and minerals. The 90 steel spectra, which are included, consist of:
- Stainless steels
- Alloy steels, Ni-based, Cu-based alloys
- Tool steels
- Carbon steels
Also, the library contains more than 50 silicates and other geological standard materials for identifying environmental and mineralogical components.
Using the library, the top three matches for the unknown sample are displayed with numerical values of the goodness of fit % along a spectral overlay confirming the details of spectral peaks fit.
Figure 1. Spectrum extracted from the map visibly and numerically identifies this phase as SbS with a much higher fit % than CaSO4 even though they contain common elements despite the challenging Sb and Ca peaks.
Spectrum Match is the fastest way to achieve conclusive material characterization solutions even with peak overlaps causing interference, as the quantification numbers are less sensitive to changes in acceleration voltage, geometry, and detector characteristics.
Resources
Product Bulletin