In XRF sample analysis, a sample is excited by high–energy photons (x-rays and/or γ-rays) and the sample’s approximate elemental chemistry is determined nondestructively and rapidly — in as little as a fraction of a second — by measuring the characteristic fluorescent x–rays emitted by each of the atomic elements in the sample.
The overall analytical x-ray instruments market is composed of three broad market segments that use different techniques and different instruments: the x-ray diffraction (XRD) segment; the wavelength-dispersive x-ray fluorescence (WDXRF) segment; and the energy-dispersive x-ray fluorescence (EDXRF) segment. Within the latter segment, the largest and fastest-growing market is for portable x-ray fluorescence (XRF) instruments. Handheld and portable benchtop XRF analyzers have been used for a wide range of applications for many years. X-rays were discovered in 1895 and first applied to the chemical analysis of minerals in 1922. The first energy-dispersive x-ray fluorescence (ED-XRF) analytical instruments were introduced in the 1960s; these early instruments required operators to manually calculate calibration curves on graph paper to measure one to four elements. By the early 1970s XRF was demonstrated to be a viable, non-destructive analytical technique for determining trace level elemental concentrations in samples. The first portable XRF instruments were introduced in 1978, and the first portable XRF units capable of internally storing calibrations were introduced in 1984. Niton Corporation, now part of Thermo Fisher Scientific, introduced the first one-piece, handheld XRF instruments in 1994.
Handheld XRF analyzers are used for lead-based paint testing, other environmental testing, metal alloy testing, mineral exploration and mining, materials compliance testing for hazardous substances and other testing applications.