Chemiluminescence Atmosphere No_x Monitoring Instrumentation, System Optimization Design

The pollution of the environment is one of the serious problems with the progress of industrialization. In recent years, NOx (NO & NO2) is gradually becoming the primary pollutant in atmosphere because the number of mobile is rapidly increasing.The monitoring of atmosphere quality is the guide of atmosphere pollution prevention and cure. An atmosphere quality monitor network with appropriate distribution and rapid reaction in city area is an important ensurance for atmosphere pollution prevention and cure. But at present NOx analyzers for monitoring of atmosphere quality in our country is almost all imported The price and maintenance of the imported analyzer is too high to make them widely used, which serious affects the process of atmosphere pollution prevention and cure. Hence, Environmental Protection Agency of Guangzhou seted up the project of "Domestical Research & Production of NOx Auto-Monitoring System for Atmosphere Quality Monitor " which is undertaken by our laboratory.This paper is based upon the work of other members in the task team. Previously, the research of theory and the building of experimentation system have been completed. A lot of true, reliable and exact laboratorial data has been achieved Result indicates, the performances of the system meet the need of atmosphere quality monitor.On tins condition, the principle of chemiluminesce for NOx detection is studied farther. Several methods for NOx detection are compared The principle of chemiluminesce for NOx detection is the emphasis. The system of chemiluminesce for NOx detection has been built These components are studied. The researchful experimentation is done in the system. The parameters and performances of this system are explored and optimized The building of mis instrument and the evaluation of performances are the emphasis in the paper. The achievements shown in this paper are as follows: 1. The principle of chemiluminesce for NOx detection is studied farther. The principle of chemiluminesce for NOx detection is the emphasis.2. The system of chemiluminesce for NOx detection has been built These components are studied. The mechanical component includes the designment and building of box and panel. The airflow component includes the designment and building of airflow and chamber, and the introduction of converter, ozonator and filter. The circuitry component includes the designment and building ofcircuitry. The temperature monitoring and controlling and PMT are the emphasis. 3. The researehful experimentation is done in the system. The results shown in the experimentation are as follows: The chamber vacuum is -0.001Mpa, the ozone flow is 0.3 LPM, the span flow is 1LPM, in these conditions the sensitivity of detection reaches the peak. The linearity relation between the output count rate and NO concentration is achieved. The ratio between the count and the concentration of NO (ppb) is 0.49 count/ppb. The best Mo converter working temperature is 350#. The concentration of NO2 had better be below 1800ppb. The results shown in the experimentation indicates the system satisfies the needing of the atmosphere monitoring of NOx.