MEASURING APPARATUS OF TRACE ELEMENT IN GAS

PURPOSE:To obtain a measuring apparatus by which a trace element in a high- temperature gas is measured in situ by a method wherein an ICP generation part and a light-receiving part are constituted respectively as freely detachable single units. CONSTITUTION:An ICP generation part 10, a solenoid 2 and a plasma-gas entrance 3 are formed as units so as to be freely detachable, and they are mounted on, and attached to, a treatment device 5 through which a measuring gas flows. A plasma gas is sucked into the generation part 10 from the entrance 3, and the solenoid 2 is electrified from a high-frequency power supply 1. An ICP plasma 4 is blown into the device 5 from the generation part 10, various kinds of atoms are excited, and optical spectra which are peculiar to the respective atoms are generated. An interference filter 6 and a light-receiving device 7 are formed as units so as to be freely detachable, they are coupled to a light-collecting part 9, the intensity of a desired atomic spectrum is captured as a signal, and an atomic density is measured by a signal processing part 8. In addition, the width and the depth of the plasma are made large, the amount of collected light of the light-collecting part 9 is made large, and an S/N ratio is improved. A noise is generated mainly by the background spectrum of a plasma flame and by its change, and the S/N ratio can be improved when a flame size is made large.