CCD磁动式氧含量分析仪的分析与设计

介绍常见气体磁化率，利用氧气顺磁性，且磁化率明显高于其它气体的物理特性，分析磁动式测量混合气体中氧气含量的方案。通过在非均匀磁场悬挂一对充氮玻璃小球构成测量池；采用光杠杆对哑铃球扭转的角度信号进行放大，由CCD对光点位置信号进行探测，以提高分析仪灵敏度和精度；由NO、NO2的磁化率特性分析这两种气体对分析仪的影响，说明测氧仪的应用环境。通过对CCD像元值随气体氧含量、温度变化规律的分析，得出分析仪的分辨率可达0．048％以上；CCD像元值随氧含量变化、随温度变化基本呈线性关系，数据处理后可使仪器有较高的精度。

Analysis and design of CCD magnetomotive oxygen content analyser

This paper introduces the magnetic susceptibilities of common gases. Based on the physical characteristics that oxygen is a paramagnetism gas and its magnetic susceptibility is obviously higher than other gases, a magnetomotive design scheme is proposed and analyzed to measure the content of oxygen in mixed gases. A measurement pool is made by hanging a pair of nitrogen-filled small glass balls in non-homogenous magnetic field. The angle signal of the dumbbell ball torsion is magnified using light lever. In order to enhance the sensitivity and accuracy, CCD is used to probe the light signal spot. According to the magnetic susceptibilities of NO and NO2, the influences of these two gases on the analyzer are analyzed, and the application environment for the oxygen detector is discussed. The changing relationship of CCD pixel values with oxygen content and temperature is analyzed, which concludes that the resolution of the analyzer can reach to 0.048% or better. The curves of CCD pixel values versus oxygen content and temperature basically appear linear characteristics, and through data processing better measurement accuracy can be achieved.