Research On Intelligent Technology Of Gas Chromatography

Chromatographic Analysis is a very important method of modern separating and analyzing. GC (Gas Chromatography) is an important sophisticated analyzing device. It has been played a great role in medication, environmental protection, foodstuff procedure, oil industry, chemical industry, scientific research, the quality and technical supervision, etc.The development of GC instrument is a complicated systems engineering, involving knowledge of analytical chemistry, mechtronic, automation, computer science, etc. The study on how to use technology of computer, intelligent instrument, electronics and new materials, new techniques to increase the intelligent level of GC is a mater of great significance. This dissertation systematically explicates the intelligent technology of GC, in the background of the GC2090 Gas Chromatograph development project developed by Jinan JingRuiDa Analytical Instrument Co. Ltd and Intelligent Detection and NC laboratory of Mechnical engineering School of Shandong University.Five parts which are signal acquisition and processing, hardware design of GC's spectrogram and auto-balance, software design, automatic sampler design and system debugging are introduced in this dissertation. Firstly, the dissertation introduces the origin of topic, the application, the theory and future trends of intelligent instrument. On the basis of detection principle of chromatography, a high precision microcurrent measurement circuit was designed for GC instrument. Spectrogram and auto-balance are explicated in detail. According to the practical application of GC instrument, developing process and designing method of hard-ware system is given here, which contains electrical parameters, chip selection and circuit design. Then the detail developing steps and optimizing methods of software system are summarized on the base discussed above. In the data processing, the dissertation provided a method that detects the wave crest by fitting data with the curve based on algorithm of interpolation. After using digital filter, the chromatogram data sampling, data storing, qualitative analysis and quantitative analysis are realized. According to the requirements of GC sampling accuracy and efficiency, automatic sampler has been deeply studied. The correctness of the system is further verified on the overall performance assessment. In the end the application and developing trend of Gas Chromatography in the future has also been discussed.