An X-ray fluorescence (XRF) spectrometer is an x-ray instrument used for routine, relatively non-destructive chemical analyses of rocks, minerals, sediments and fluids. The emitted X-rays have energies characteristic of the specific elements in the sample, allowing for rapid elemental analysis. It works on wavelength-dispersive spectroscopic principles that are similar to an electron microprobe (EPMA). The operational principles of this system are based on. Spectroscopy is the study of light as a function of wavelength that has been emitted, reflected or scattered from a solid, liquid, or gas. No single chapter can cover this topic.