| In this paper, the first purpose of the research and significance of indoor air quality (IAQ) research has been a very long time to have an initial idea of IAQ understanding that a specific relationship between pollutants and disease, but not comprehensive study of IAQ. Today, with the closed building structure and interior of the increase in office staff, IAQ is becoming more and more important. Detection of the IAQ at home and abroad has more than 30 years, and on various indicators of air pollution, as well as a comprehensive set of indicators, but a portable yet fast and universal detection methods, the subject is based on portable and quick to put forward on the basis of air quality detection. First introduced the basis of air quality-related knowledge, to explain the typical indoor air quality definition: Denmark FANGER scholars on the definition of the Royal Institution of Engineers CIBSE construction equipment as defined in the proposal, the United States, such as the definition of the ASHRAE. Indoor air quality and then on the research background, the impact of factors, sources of analysis, research direction, and so on to be a few brief details of the characteristics of indoor air and the impact of factors: indoor thermal environment, indoor environment, indoor facilities , construction maintenance of the structure, impact, air conditioners, radiation, such as radon, indoor air quality, introduced the general approach, as well as detection methods improve air quality, including air quality testing of the various indicators are introduced. Then discussed in detail the quality of indoor air detector hardware design: First introduced portable indoor air quality detector system hardware structure and function, the equipment to 8-bit MCU AT89S52 as control core, designed and built the system's hardware platform completed the concentration of toxic gas to enlarge the collection signal conversion circuit, liquid crystal display circuit, alarm circuit, such as sound and light design.The instrument to achieve the concentration of toxic gas humidity and temperature signals and signal acquisition and display, and standard features such as sound and light alarm. This chapter focuses on the analog signal acquisition circuit and to the main controller for the Center for Digital Circuit Design and working principle. First of all, to discuss acquisition of toxic gas sensor module selection and analog amplification circuit design problems, and finally to discuss the system's peripheral interface circuit module, including the liquid crystal display, such as sound and light alarm, the realization of the external interface of the circuit module and the hardware interface AT89S52.Then introduced the indoor air quality of the software design detectors: portable indoor air quality can only monitor the software design for a more detailed account. Software uses the idea of modular design in order to C51 single-chip high-level language programming. At the beginning of the structure of the main program flow chart is given, and then separately for each sub-process software module introduced.Finally, anti-jamming system design and the conclusions and outlook issues discussed: The sources of interference and its route of transmission, followed by hardware and software from the two aspects of the system adopted by the anti-jamming measures to enhance the reliability of the system and anti-immunity 1000. The main conclusions: the system of comprehensive utilization of sensor technology, automatic detection technology, and micro-controller technology, the development of a set of indoor air quality monitoring is easy to operate, simple and practical automatic monitoring system.System software and hardware designed, in which single-chip modular software design process, the modules are independent of each other to improve system reliability and scalability of the entire system has a high cost performance. C51 language programming system, program structure clear, display a very friendly interface, making the operator in the use of the system is in operation as a real instrument, like the control. System independent, a reasonable configuration. Single-chip part of which can operate independently, you can test drive through the PC, which provide users with different options to a certain extent.Verification by the simulation run, the system has fast response, simple operation, reliable work. Recommendations for further research: the system sets all selected sensors, switches in one, to direct the standard analog signal output of the sensor, which will undoubtedly increase the cost, the future use only low-cost sensors, and signal amplification and conditioning part can design their own circuits. A variety of indoor environmental factors interact, and the system control output signal is only a simple percentage of the volume, which obviously does not meet the requirements of high-precision control, should be introduced into the fuzzy algorithm, expert system technology to further enhance the level of intelligent decision system . System can be developed into a multi-monitor mode, which can be detected at the same time a number of environmental indoor air quality, passed through the PC serial communication integrated handle. Due to limited conditions, the system has not been a large number of experiments to verify, so the actual reliability of the system need to be further verified, in order to enhance the practicality of the system.
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