METHOD AND APPARATUS FOR DETECTING TRACE IMPURITIES IN IMPURE INERT GAS

摘要

PURPOSE: To detect the trace impurities of a reducing gas or nonreducing gas by separating the inert gas by gas chromatography, subjecting the gas to ionization discharge, and bringing the gas into contact with mercuric oxide. CONSTITUTION: An inert gas containing impurities is separated by means of a separation column 8 for chromatography by supplying the gas to the column 8 from a cylinder 4. The separated inert gas is led to an ionizing device 12 for ionization discharge. The ionization discharge is performed by passing the inert gas around an node or cathode while the electrode is maintained at a grounding voltage of 150-1,000 V. A nonreducing gas of CO2 and CH4 which are impurities are dissolved around the electrode and CO and H are isolated. Then the inert gas is made to react to mercuric acid so as to discharge mercy vapor by making the inert gas to flow through a mercuric acid bed 15. The mercury vapor is detected by means of an optical sensor 17 and the concentration of the impurity is detected. Therefore, the reducing gas and nonreducing gas can be microanalyzed.