用于负压下气体分析的气相色谱仪的研制

The Development of a Gas Chromatograph Used in Gas Analysis Below Atmospheric Pressure

介绍一种可同时分析负压样品中常量O2，N2，CO和微量CO2的自制专用气相色谱仪。仪器在负压下取样，经活塞升压后进样。在流程中样品气同时进入并列的色谱柱，再分别检测。常量组分使用热导地（TCD）检测，微量组分使用氦离子化检测器（HelD）检测。CO2的检测灵敏度为10-6（V／V）量级。实验表明，仪器结构简单、操作方便、稳定性好，适合于负压气样的在线分析。负压气样中全组分的分析方法具有推广价值。

During the process of setting up a carbon monoxide infrared laser generator, it's necessary to analyze the gaseous components produced in laser cavity under reduced pressure for understanding its charging regularity. In this paper a self-made gas chromatograph for analysis of some special gas mixtures is described. This instrument can analyze O2, N2, CO(with normal contents ) and trace CO2 simultaneously below atmospheric pressure. The gas sample below atmospheric pressure was taken into a small piston cylinder and then compressed by pushing the piston for injection. The injected sample was carried by He into two parallel chromatographic columns and detected separately. The gases with normal contents were detected by a thermalconductivity detector(TCD) and the trace CO, was detected by a He ionization detector(HelD). The detection sensitivity of CO2 is in the order of magnitude of 10-6V/V. The experimental results show that this instrument with advantages of simple design, easy operation and good stability is suitable for on-line analysis of gas samples below atmospheric pressure. We have successfully analyzed on-line the gaseous components produced in the laser cavity by using this equipment. The technique described here can be used for complete analysis of gas samples below atmospheric pressure in many other fields.