Links in this section:

Introduction
Evolution of WDS technique
Basics of WDS
Diffraction
Crystals
Detectors & Geometry
Comparison of EDS and WDS
Qualitative Analysis
Quantitative Analysis
Mapping
Summary

Qualitative Analysis

Using normal ED operating conditions it is not always easy to positively identify peaks due to trace elements. However, by increasing the beam current and slowly scanning over the peak position using the WD spectrometer, trace elements can be reliably identified.

Fig 6. shows the ED spectrum from an alloy containing 0.15wt% Si. The red line shows the expected peak position for Si, but it is difficult to be positive about reliable identification. In the WD spectrum (fig 7), the improvement in peak to background ratio means that there is no doubt that Si is present .

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