Wavelength Dispersive Spectroscopy

WDS chemical analysis

Wavelength dispersive spectroscopy (WDS) isolates characteristic X-rays generated by the sample during analysis to create quantitative compositional data and is able to quantify elements at very low abundances. WDS is a non-destructive, high resolution technique well-suited for natural and synthetic solids, and complements energy dispersive spectroscopy (EDS). Our WDS system is currently standardised for following elements. Any elements of interest that are not part of our standardising suite can be identified using EDS. 

<p>WDS periodic table of elements</p>
<p>EDS vs WDS</p>

WDS vs EDS

Modern EDS systems create largely comparable data to that produced by WDS at a faster rate. However, WDS analysis has an improved peak resolution compared to EDS and also collects a background reading, generating accurate data with low errors even for elements in low abundance (< 1%).  WDS can also help in refine EDS data, particularly where two elements share an overlapping spectra. 

Benefits of WDS

By using SEM-WDS as opposed to an electron microprobe (EPMA) we are able to collect data at significantly lower probe currents, thereby reducing the interaction volume. This means that we can accurately analyse the composition of small features without contaminating the spectra with X-rays released from nearby features, as well as reducing damage to the sample from the electron beam. In addition, our SEM-WDS system stores standardisations for each set of best operating conditions and does not require standardising before each analysis, saving a large amount of time.