When sufficient energy light waves (x-ray or photon) are absorbed by an atom, the inner shell electrons are excited to an outer shell or removed completely. The empty inner shell that remains is ‘filled’ by electrons from an outer shell of the atom. The difference in energies between the two shells involved is excess energy; which, when generated in this process, is emitted as radiation (fluorescence). In a given element the energy difference between two specific orbital shells is characteristic of that element and is always the same.
Therefore, the emitted light wave will always have the same energy...by determining the energy emitted by a particular sample XRF analyzers are able to identify the element(s) involved.
XRF Compared to Other Analytical Techniques
Other methods of elemental analysis or chemical characterization (atomic absorption, inductively coupled plasma spectroscopy, wavelength dispersive XRF) are either destructive, require massive units, are limited in function, or are too expensive when compared to the energy dispersive x-ray fluorescence model. The benefits of EDXRF in comparison make it the preferred method for a variety of applications needs.
The Major XRF Components
There are three major parts in XRF analyzers that affect performance and capabilities. First, an x-ray source known as an x-ray tube (generally 40-60kV, 50-300W) emits an x-ray beam into the sample being analyzed. After this beam excites and displaces electrons the resulting energy that is characteristic to the element is emitted as a wavelength and collected by another critical component, the detection system. The type of detection system varies in each model, providing different benefits that suite a particular testing need. A last component is the software package; which is based on algorithms developed for specific applications and processes the information collected by the detection system.
Xray Fluorescence Components in MeasurementThe components utilized are important for an instrument’s daily performance (accuracy, speed, repeatability) and the analyzers long-term life. Eastern Applied Research selects only top performing components for repair services and has teamed with manufacturers that source only reliable components for the new analyzers offered.