METHOD FOR MEASURING TRACE QUANTITY OF HELIUM IN METAL

摘要

PROBLEM TO BE SOLVED: To avoid the obstruction of measurement or dilution action caused by coexisting gas by collecting the sample gas generated by heating a sample metal by a sampling bag and cooling the same by an adsorbing pipe to remove impurities before measuring helium(He). SOLUTION: A sample metal 1 is heated to about 2,000 deg.C or higher in a heating furnace 2 to extract He in the sample metal 1 and Ar gas is sent from a carrier gas cylinder 3 to force out He. He is separated from coexisting gas in a column to be collected by a sampling bag 7 through a TCD cell 5 and sent to the sorption pump 13 in an adsorbing pipe 12. The adsorbing pipe 12 is cooled by a cooling medium to be packed with an adsorbent 14 to trap gas other than low b.p. gas such as hydrogen, He or the like. Thereafter, the He- containing gas is sent to the detector 15 of a mass analyzer for analyzing the mass corresponding to the mass of He to measure the amt. of He to record the same on a recorder 16. This measured value is compared with a calibration curve due to the gas known in the concn. of He of a standard cylinder 17 to calculate an accurate He amt. and the concn. of He in the sample metal 1 is calculated.