The Fundamental Parameters Working Group is an international initiative launched by LNE, PTB and TU Wien, under the auspices of the European X-Ray Spectrometry Association, to improve the knowledge of the fundamental parameters used in X-ray spectrometry, bringing together key players from international X-ray instrumentation companies as well as various institutes from the academic sector. The FPWG activity is carried out in the following expert groups:

1. Prioritisation of FP requirements (energies, elements, uncertainties)

2. Experimental facilities (needs for improved instrumentation)

3. Theory & codes – challenges: competent use and update of software

4. Compilations (need for new strategies), data processing

5. Definition of technical terms

6. Establishment of a common data base accessible to the publicntrada