Studies On Detection System Of The Gas Mixtures

With the rapid development of China's economy, people's living standards have been significantly improved, natural gas has been widely used in the industrial field, and also in people's daily life. However, in recent years, the non-standard use of flammable gases and the product quality problems resulting in natural gas leak, gas poisoning and explosion. Therefore,in view of the current gas detection, this paper proposes a hybrid gas detection system research.Traditional method about gas detection mainly use the gas sensor and multiple instruments; but the electronic nose which based on the sensor array because of its structure's complexity, the price is too expensive to popularize;The gas detection system with the low performance has low accuracy and low stability so that it is unable to meet the demand.According to the requirement of natural gas detection, this paper designs a gas detection system based on FPGA, which can detect the methane, carbon monoxide and hydrogen sulfide in natural gas precisely. This system includes two parts of hardware and software. The hardware part of the system as the controller, mainly including FPGA minimum system,multiple sensor acquisition circuit, signal conditioning circuit?sampling hold circuit and filter circuit?, an alarm circuit, JATG/AS circuit and GPRS circuit, this part can realize the collection, analysis and transmission of gas concentration information. The software includes FPGA programming and PC programming. The programming of the FPGA drives the A/ D converter, GPRS, external storage and the buzzer,its also improve the detection system's accuracy by using the digital filter; PC software using Visual C + + 6.0 and socket interface realizes the GPRS data receiving, alarm messages, and message prompt function, and the data displays to the main interface with picture.Through running this system overall, and analysis the CH₄,H₂S and concentrations CO,so that we get the results of detection and analysis, and this system has reached the requirements of design.The experimental results show that the measurement error of the system has significantly reduced, and improves the measurement accuracy.