The Development And Experimental Research Of Odorous Gases Detecting System

As a special environmental pollution, odor pollution has seriously affected the people’s production and life, and even threatens people’s lives and safety. Therefore, enhancing the detection of odorous gases in the atmosphere is related to the people’s health, and odorous gas detection is an important basis for environmental governance and environmental law enforcement. Therefore, the development of malodorous gas detection devices is imperative.Firstly, this paper reviews the common methods of gas detection and makes them comparison, then chooses the GC as the detection method; then, it describes the origin and development at home and abroad of GC in detail. Based on GC technology and combined with micro-fluidic technology, we design the odor gas detecting systems.The odorous gas detecting system consists of the gas system, the injection system, the separation systems, the detection systems, the control systems, and the data processing system. Firstly, under the premise of stable pressure and flow of the carrier gas in the gas system, we design and complete the auto sampler module to achieve sample collection and injection automatically; Secondly, with the micro-fluidic chip instead of the traditional gas separation column and photo ionization(PID) detector, it makes the system size reduce greatly and miniaturization goals achieve. Thirdly, this paper discusses the control system based on STM32 single chip microcomputer. In terms of hardware, we design and complete the control circuits of gas injection, detection and data acquisition, and the serial communication circuit; In terms of software, we write system detection programs and LCD control programs, each part of them described in detail.We study the results of the structural and physical parameters to the system. By the study of the column diameter, length, fixed parameter, we determine the size and the coated substance type of the micro-fluidic chip. In this paper, it is described in detail what the pressure, flow, temperature and other physical parameters of the system affect the results of experiments, which provide the basis for setting parameters in which to detect a variety of malodorous gas mixtures.Finally, for the separated and detected gas components, this system has achieved its qualitative and quantitative analysis. Experimental results show that the system can detect a plurality of gases at the level of ppm and detection accuracy of 3% with good repeatability. This paper also describes the present deficiencies and improvements in the research work, and discusses the future development direction of the research.