| 摘要 |
<p>PURPOSE:To provide a small-sized and high-sensitivity gas analyzing device to perform the quantification of the ultra-low concentration water content of a high purity gas (at ppb level). CONSTITUTION:A gas analyzing device is composed of an ion source 5 to introduce a specimen gas 1 and ionize and a drift tube 16 to contain a pure gas with the impurities reduced by a purifier 9 down to below 1 ppb. The drift tube 16 includes a shutter 13, electrode 14, and sensor 15. The shutter 13 separates the ion source 5 from the drift tube 16, and also functions to reduce mixing of the specimen gas 1 with the pure gas 10. The concentration of the impurities is determined from the ratio of main component ions separated by the drift tube 16 to the total ion intensity. To analyze the impurities (water contained) of a low concentration as low as ppb region, the duration of ions in the drift tube 16 is set short in relation to the mean time of reaction of the specimen gas main ions with the water contained.</p> |
