Classification of X-ray fluorescence spectrometer

    X-ray fluorescence spectrometer can be divided into two categories: wavelength dispersive X-ray fluorescence spectrometer (WDXRF) and energy dispersive X-ray fluorescence spectrometer (EDXRF). The main components of wavelength dispersive spectrometer include excitation source, spectrophotometer, goniometer and detector, while energy dispersive spectrometer only needs excitation. Source and detector and related electronic and control components are relatively simple.
Wavelength dispersive X-ray fluorescence spectrometer uses analytical lines of crystal to distinguish the elements to be measured. According to Bragg's law, the spectral line wavelength of the elements to be measured can be obtained by measuring the angle: n_ lambda = 2dsina_ theta (n = 1,2,3...). In the formula, lambda is the wavelength of the analytical spectral line, D is the lattice spacing of the crystal, theta is the diffraction angle, and N is the diffraction order. The diffraction angle of the analytical spectral line can be measured by goniometer, and the wavelength of the corresponding elements can be calculated by using the above formula, so as to obtain the characteristic information of the elements to be measured.
The energy-color scattering line fluorescence spectrometer uses an energy detector to measure the charge collected by the detector, and directly obtains the characteristic ray energy of the element under test: in Q=kE, K is the photon energy of the incident ray; Q is the corresponding charge generated by the detector; K is the response of different types of energy detectors. Parameters. The charge amount is proportional to the incident ray energy, so the characteristic information of the elements to be measured can be obtained by measuring the charge amount. The characteristic spectra of the elements to be measured need to be obtained by using a certain excitation source. At present, the conventional excitation sources are mainly ray tube and isotope excitation sources.