ATOMIC ABSORPTION ANALYZER

PURPOSE:To permit sepn. of only the true background signal by using light sources such as hollow cathode lamp and deuterium lamp. CONSTITUTION:The output of a photomultiplier PM is inputted via selector switches S1-S5 to sample holding circuits RS1-RS5 and is held therein. The switch S1 samples the photometric output during lighting of the hollow cathode lamp HCL with small current, the switch S3 the photometric output during lighting of said lamp with large current and the switch S4 the photometric output during lighting of the deuterium lamp D, respectively. On the other hand, the switches S2, S5 sample the photometric output during the period when neither of the lamps HCL, D are fed to a sample atomization part ATM. These sampled signals are sent through subtraction circuits SB1-SB3 to logarithmic converters LG1-LG3, by which the signals are converted to absorptivity signals; thereafter, the output of the converter LG2 is subtracted from the output of the converter LG1 in the subtraction circuit SUB, by which the signal of the absorptivity value of the sample element is obtd. Said signal is inputted to a signal processing circuit SIP. The output of the circuit SB3 is converted to the absorptivity signal by the converter LG3.