Design And Experimental Study Of In-situ And Synchronous Detection System Of CO₂ Gradient

Carbon dioxide (CO2) concentration is one of the most important data need real-time monitoring and analysis in many fields, The concentration of carbon dioxide monitoring was wildly used in agricultural production, environmental protection, medicine and health, industrial production, aerospace and other fields. Carbon dioxide is an important factor to cause the greenhouse effect, in the modern industrial society, excessive burning of coal, oil, natural gas produced lots of carbon dioxide into the atmosphere, causing a gradual increase in atmospheric carbon dioxide concentration in recent years. At the same time, carbon dioxide was the main raw material of plant photosynthesis, monitoring and measurement the carbon dioxide concentration in field has great significance at agricultural information collection, carbon sequestration, carbon dioxide fertilization, improving the yield of crops.In order to accurately measure the carbon dioxide concentration gradient near the farmland ground, reduce error caused by manual measurement, and realize the automatic measurement, this paper chooses GPRS technology as a solution for transmission technology. GPRS network has features of real-time transmission, low cost, wide range of network coverage etc.. It’s relatively low maintenance cost, convenient installation, easy to realize.The design of the carbon dioxide concentration gradient in situ measurement system mainly includes the following:(1) Mechanical collection structure design:mechanical acquisition structure is mainly composed of a quantitative pumps, the straight type two position three way solenoid valves and pipes, there are 5 branches, temporary storage for gas and measured;(2) Electrical control circuit:The control part of the control chip uses STM32 to control electrical valve groups, collect sensor information and communicate with the host computer.(3)The upper and lower machine software design:Mainly includes client driver and PC data display and storage system.(4) Experiment design:The two part through indoor and outdoor experiments, collecting carbon dioxide concentration gradient distribution, test reliability of the device;Design of a carbon dioxide concentration gradient distribution in situ measurement system in this paper, the system uses wireless transmission system based on GPRS network and STM32 control system, the installation in the field can be automatically measuring carbon dioxide concentration gradient distribution and the data is transmitted to the PC server system. The design mainly includes mechanical measurement, data acquisition module and electrical control module. Experimental results show that the distribution relationship of farmland carbon dioxide concentration gradient, and realize the automatic acquisition of field information.