Röntgenfluoresenssimittaus

Röntgenfluoresenssimittaus, or X-ray fluorescence (XRF) measurement, is a non-destructive analytical technique used to determine the elemental composition of solid, liquid, or powder samples. It identifies and quantifies elements by measuring characteristic X-rays emitted when the sample is irradiated with an external X-ray source or gamma rays. The method can detect a broad range of elements, typically from light elements such as sodium or magnesium upwards, depending on the instrument configuration and the sample matrix.

In operation, the primary X-ray beam ejects inner-shell electrons from atoms in the sample. As electrons from higher shells fill the vacancies, atoms emit X-rays with energies unique to each element. XRF instruments are mainly categorized as energy-dispersive (EDXRF) and wavelength-dispersive (WDXRF). EDXRF uses energy-dispersive detectors, while WDXRF employs crystal analysers for higher spectral resolution. Systems range from portable handheld devices for on-site analysis to laboratory benchtop spectrometers with higher resolution and flexibility.

Quantitative analysis relies on calibration against standards or fundamental parameters approaches. Matrix effects, sample geometry, surface roughness, and absorption influence results and are addressed through appropriate calibration, reference materials, or correction algorithms. Detection limits vary by element and matrix; light elements are more challenging to quantify. Results are commonly expressed as mass fractions or parts per million.

Applications span geology and mining, metallurgy, environmental monitoring, archaeology and cultural heritage, pharmaceuticals, and industrial process control. XRF offers rapid, non-destructive analysis with minimal sample preparation, though it provides limited information on chemical states or light elements. Safety considerations include ionizing radiation exposure, so devices incorporate shielding and interlocks and operation adheres to applicable regulatory requirements.