ARM Airborne Continuous carbon dioxide measurements

The heart of the AOS CO2 Airborne Rack Mounted Analyzer System is the AOS Manifold. The AOS Manifold is a nickel coated aluminum analyzer and gas processor designed around two identical nickel-plated gas cells, one for reference gas and one for sample gas. The sample and reference cells are uniquely designed to provide optimal flushing efficiency. These cells are situated between a black-body radiation source and a photo-diode detection system. The AOS manifold also houses flow meters, pressure sensors and control valves. The exhaust from the analyzer flows into a buffer volume which allows for precise pressure control of the analyzer. The final piece of the analyzer is the demodulator board which is used to convert the DC signal generated by the analyzer into an AC response. The resulting output from the demodulator board is an averaged count of CO2 over a specified hertz cycle reported in volts and a corresponding temperature reading. The system computer is responsible for the input of commands and therefore works to control the unit functions such as flow rate, pressure, and valve control.The remainder of the system consists of compressors, reference gases, air drier, electrical cables, and the necessary connecting plumbing to provide a dry sample air stream and reference air streams to the AOS manifold.

AOS CO₂机载机架式分析仪系统的核心组件为AOS歧管（AOS Manifold）。该歧管为镀镍铝制分析仪与气体处理器，基于两个完全相同的镀镍气室设计，分别用于承载参比气体与样品气体。此样品气室与参比气室采用独特设计，可实现最优吹扫效率。两类气室均设于黑体辐射源与光电二极管检测系统之间。AOS歧管还集成了流量计、压力传感器与控制阀。分析仪的排气流入缓冲容积，可实现设备的精准压力调控。分析仪的最后一个组件为解调板（demodulator board），用于将分析仪产生的直流信号转换为交流响应信号。解调板的最终输出为特定赫兹周期内的CO₂平均计数（以伏特为单位报告），以及对应的温度读数。系统计算机负责命令输入，进而控制设备的各项运行功能，包括流速、压力与阀门调控。系统其余组件包括压缩机、参比气体、空气干燥器、电缆，以及用于向AOS歧管输送干燥样品气流与参比气流的必要连接管路。