JPS649339A - Atomic absorption photometer - Google Patents

Abstract

PURPOSE:To enable the selection of an optimum measuring value corresponding to the concentration of a sample, by selecting a plurality of analysis frequencies different in absorption sensitivity for measurement. CONSTITUTION:A sample set in a graphite tube 26 is heated by a Joule's heat to turn into atomic vapor. Fluxes of light from a plurality of light sources 20 are made to pass through said vapor, wavelengths of analytical beams are selected by spectroscopes 28 and 29, and then the light is separated by fixed polarizers 30 into a light P11 having an oscillation plane parallel to a magnetic field and a light P12 having an oscillation plane vertical to the field. Next, the lights P11 and P12 are made to enter detector 34 alternately by a beam selector 32 and are detected by the detectors 34. On the occasion, the light P11 is affected by both atomic absorption and background BG, while the light P12 is affected by BG. By finding a difference between the lights P11 and P12, accordingly, an amount of the atomic absorption for which BG is corrected is obtained. Besides, the light fluxes entering the detectors 34 are turned thereby into electric signals corresponding to the intensities thereof, amplified 36, subjected to A/D conversion 38 and inputted to a computer 40. Then, an unknown sample is measured, and the concentration thereof is determined from a working curve and displayed 42.