Design And Study Of Gas Detection System Based On Virtual Instrument Technology

In this paper, we deeply study and research the system theory, composition, and applications of gas detection system for data acquisition, processing, analysis. Due to the need for social security, real-life need alarm detection for inflammable and explosive materials, precursor chemicals, and the distinctness of non precursor chemicals in order to ensure the safety of people's lives and property, to combat criminals. In this paper, on the basis of previous work in the laboratory, we design and develop the hardware and software systems for gas precursor chemicals detected. Using pattern recognition methods such as expert system on test results for data analysis and identification, and ultimately enables the establishment of precursor chemicals for rapid detection of gas detection devices and analysis platform.First, this paper describes the study of gas detection technology and research background of the status, then this article expatiate the meaning and content of the study. Describe the realization of the principle of the gas detection sensor technologies and the Ion Mobility Spectrometry technology detailed. We introduce the background of Virtual Instruments and the technical characteristics of LabVIEW, research and study the modulation of temperature gas sensor array and ion mobility spectra of two-component detection system and pattern recognition methods.Based on the above theory, we make acetone, butanone, acetic anhydride and other 20 kinds of volatile chemicals and precursor chemicals for the detection of objects, and realize the hardware and software design for gas detection system. It has been good detection results, for the adoption of a national acceptance. In hardware design, the core for the control is single-chip AT89S52. The design include the gas sensor array, the detection circuit, the dynamic high-frequency circuits whose frequency is changeable; Using USB2005 data acquisition card to form a rapid, high-precision real-time data acquisition and control system; in software design. We use LabView Virtual Instrument Technology to build a dual-platform system, the collection, processing, display, pattern recognition system.Using the test system in the laboratory, we carry out a large number of experiments. From experimental results, in the favorable conditions of work, the gas sensor array and the response characteristics of Ion Mobility Spectrometry has rich amount of information through the using of pattern recognition expert system approach to measurement samples for analysis, identification. It achieves good results.