Long-term Dtability Of Gas Sensor Monitoring System

With the social development and the enhancement of people's awareness of environmental quality, the attention and investment that the state on environmen-tal monitoring field is growing. With more and more application of various toxic and harmful gases, the gas sensors get more and more widely used in a variety of industrial sites and people's lives. However, in the research and production process of gas sensors, there are some factors such as low detection efficiency and accuracy, cannot real-time monitoring parameters, etc, that severely limit gas sensors's mass production and application. Therefore, it is the best way to solve this problem that developed a gas sensor monitoring system.The paper presents the design of the gas sensor long-term stability monitori-ng system, this system can monitor the gas sensors's properties in a long time and do the data saving and processing. It also can monitor the environment temp-erature and humidity to providing the reliable environment protection for the data collected by the sensors. The system is mainly comprised of power supply, temp-erature, humidity, 80 choose a line, automatic span selection circuit, display sec-tion, SD card store and PC data processing interface,etc.Monitoring system uses analog switch to designing automatic range select-ion circuit and select one in 80 circuit, transmits the analog signals through the analog switch. System uses the ARM CortexM3 LM3S1138 series as the microc-ontroller, doing the A / D collection and part of the data processing. The system sometimes needs to collect data for a long time, so the paper designs the SD card storage to deal with the large amount of data. Upper computer software uses Delphi7.0 as the development platform, it can realize the real-time data collec-tion, data curve drawing and historical data query functions.The long-term stability monitoring system has a good stability and high precision through the practical application.It can realize the monitoring of gas sensors'characteristics, and provide a powerful tool of the sensors'development.