【摘要】 针对大气氮氧化合物浓度在线检测要求,研制出低浓度氮氧化合物化学发光检测系统。其中的样气与臭氧的混合用双层喷嘴结构完成,可以使一氧化氮分子与臭氧分子在新型化学反应室内全面迅速发生化学反应,从而提高化学发光效率;将光子计数头冷却至6oC,能使光子计数器的本底信号降低到12cps以下;使用改进的多组臭氧发光器和串行气路基本上消除了臭氧本底信号;采用多点离散光源会聚光路提高了光子探测能力。实验表明,该检测系统的检测灵敏度已达到5count/1ppb。更多还原

【Abstract】 A chemiluminescene detection system for low concentration nitrogen oxide is developed in view of the demands for on-line concentration detection of nitrogen oxide in atmosphere. The mixing of sample gas with ozone is carried out with a double-nozzle structure and a chemical reaction of NO molecules with ozone molecules can be entirely and rapidly performed in a novel chemical reaction chamber. In this way chemiluminescene efficiency is improved. Through cooling the photon counting head to 6C, the background signal of the photon counter can be reduced to less than 12cps. The background signal of ozone is basically eliminated by application of modified multi-group ozone generators and serial gas line. In addition, the photon detection capability is improved by using a convergent optical path for multi-point discrete light sources. The experiments show that the detection sensitivity of the detection system has attained 5 counts/1ppb.更多还原