ES373604A1 - An apparatus for selectively measuring the intensity of fluorescent radiation. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

An apparatus for selectively measuring the intensity of a fluorescent radiation, in particular a non-dispersive x-ray fluorescence measuring apparatus for measuring the mass per unit area of a coating element of a coating of a base, said element having a number atomic which is at least an atomic number greater than that of any other element of the coating of said base and that of any other element of said base, said meter comprising an x-ray beam positioned to irradiate a localized area of said coating of the base and having a sufficient excitation potential to excite said covering element to emit a fluorescent radiation at its characteristic wavelengths, the intensity of said radiation being proportional to the mass of said coating element in said localized area of the coating, while fluorescent background radiation is produced simultaneously from any other elements of said coating and said base, and a redispersed x-ray beam radiation is produced simultaneously; a single passive filter comprising a preselected element having a predetermined thickness and a marginal wavelength of x-ray absorption slightly smaller than at least one of said wavelengths characteristic of the fluorescent radiation of said coating element, said thickness being selected predetermined such that said filter selectively transmits at least one of said wavelengths characteristic of the fluorescent radiation at its characteristic wavelength with a known percentage of absorption and said background radiations and redispersed with a higher percentage of absorption to establish a substantially optimal relationship between them to said x-ray beam excitation potential, said filter being positioned with angular displacement relative to said x-ray beam and adjacent said radiated localized area of the coating to selectively transmit the wavelength characteristic of the x-ray beam. Fluorescent radiation at said substantially optimum ratio; and a detector positioned relative to said filter to receive the characteristic wavelength transmitted from the fluorescent radiation of said coating element and produce an output signal that is substantially proportional to the intensity of said fluorescent radiation intensity detected from said fluorescent element. Coating, said output signal being substantially representative of said mass per unit area of the covering element of the base being measured by said meter. (Machine-translation by Google Translate, not legally binding)