An atomic absorption system comprising a radiation source that emits spectral line radiation characteristic of an element to be analyzed, an analysis region open to passage of the beam of radiation from the source and in which a sample of the substance to be analyzed is atomized, source control means for alternately energizing the source at a first intensity level to provide a radiation output that has a narrow spectral line at a wavelength of an element to be detected and at a higher intensity level to provide a radiation output of broader wavelength with intensity suppression at the wavelength of the narrow spectral line, electronic transducing means for developing an electrical signal corresponding to the sensed radiation intensity of the radiation beam that passes through the analysis region, and a log ratio circuit that utilizes integrated electrical signals corresponding to the two source energization intensity levels to provide background corrected concentration information on the element of interest in the analyzed sample.