The Research Of Key Techniques For Compound Odor Electronic Nose Monitoring System

With the development of the industry and the rising number of private cars, there are more and more environmental problems. The air we lived on is polluted by the construction dust, vehicle exhaust and industrial waste gas. In modern society, people pay more attention to the environmental problems since their environmental protection consciousness is gradually enhancing. In addition to PM2.5, the odor has serious impacted on people’s life among atmospheric pollution. Therefore, the odor has become the key monitoring objects. But the composite odor monitoring system in domestic is not mature and the mature odor monitoring system at abroad is expensive. So, it is urgent to develop a set of high quality and inexpensive odor monitoring system.Based on the research of the existing odor measurement methods at home and abroad, combined with electronic nose technology at present, this paper has conducted the research and improvement on the key technology of compound odor electronic nose monitoring system. In this paper, the key improving technology includes the following aspects: the design of air chamber for the measured gas, the design of the sensor circuit, the design of the upper machine calibration system, the odor value calculation model design, signal processing and researching the new odor value computation model. The improved composite odor electronic nose detection system is mainly composed of sensor array, the sensor signal conditioning circuit, sampling system based on c8051f020 MCU(Micro Controller Unit) and PC system.So far, the triangle odor bag method and the instrument measuring method are the main odor detecting methods. The disadvantages of the triangle odor bag method is slow speed detection and time-consuming, what is worse, the detecting results are easily affected by man-made factors. The instrument measurement is expensive and can only detect a single substance. Compared with the above two methods, the odor detecting system in this paper has the advantages of fast response, high stability, high accuracy, broad scope of application.Now the system can monitor the H2 S, NH3 and the volatile organic compounds VOCs, The system measurement range from 17 ppb to 100 ppm.Experiments show that this monitoring system,s stability, sensitivity, accuracy can realize complex odor continuous monitoring and meet the demand of reality. So this electronic nose detecting system has broad application prospects.