JPS54134490A - Atomic absorption analyzer - Google Patents

Abstract

PURPOSE:To eliminate the error due to the background absorption by using as a light source both a hollow cathode lamp and a heavy hydrogen lamp to divide the spectrum obtained into portions containing and not containing the resoannce spectrum and by obtaining the difference between the two detecting signals. CONSTITUTION:The beams from a hollow cathode lamp 1 and from a heavy hydrogen lamp 2 which is lit in a pulsating manner by a pulse power source 3 are overlapped by a semitransparent mirror 4 and are made to pass through an atomizer 5 so that they are subjected to spectroscopy by a monochrometer 6. After that, the overlapped light is divided by a separating mirror 7 into a flux of light L4 containing the resonance spectrum S1 of the element being measured and the spectrum S2 therearound and the flux of light L3 containing only the spectrum S2, both of which are detected through detectos 9 and 8 by synchronous detecting circuits 11 and 10, respectively. The difference inbetween is then obtained by a difference detecting circuit 12 thereby to obtain the measured value which is compensated in respect of the influence of the background absorption while coming only from the resonance absorption of the element. Incidentally, the hollow cathode lamp may be lit in a pulsating manner in place of the heavy hydrogen lamp.