The atoms and ions contained in the atomic vapour are excited into emission of radiation. The radiation emitted is passed to the spectrometer optics via an optical fibre, where it is dispersed into its spectral components. From the range of wavelengths emitted by each element, the most suitable line for the application is measured by means of a CCD.
The radiation intensity, which is proportional to the concentration of the element in the sample, is recalculated internally from a stored set of calibration curves and can be shown directly as percent concentration.