０前言合成氨厂大量采用自动气体分析仪表。该仪表能直观地连续指示和记录生产过程中各种气体成分的变化，使操作人员及时调节工况，稳定生产过程，保证产品、中间品的质量。许多重要部位的分析仪表还常带有联锁信号，当被测的成分越限后能报警或自动停车、自动换车等等，... 0 Introduction Synthetic ammonia plant uses a large number of automatic gas analyzers. The instrument can visually continuously indicate and record the changes of various gas components in the production process, so that the operator can adjust the working conditions in time and stabilize the production process to ensure the quality of products and intermediate products. Many important parts of the analytical instruments are often linked with an interlock signal, when the measured composition of more than limit alarm or automatic parking, automatic car change, etc., ...