Design And Implementation Of Vehicular Infrared Gas Analyzer

With the development of society and the improvement of people's living standard, more and more attention has been paid to the environmental protection and personal safety. Meanwhile, the demands for quantitative monitoring and control of the CO2, CO and other gases existed in living and working environment is becoming even more intense.At present, with the development of infrared detection technology, the advantages of gas detection by means of infrared gas absorption principle have been more and more obvious.By using the ATmega16 microprocessor to process datas, based on infrared gas absorption principle the paper have been realized the measurement of gas concentration.This paper analyzed the status of the gas detection research and development trends, then based on the theoretical of infrared gas detection, built a hardware platform of master-slave control, the master communicate with the slave through UART or SPI.The slave server as an independent gas concentration detection module, which realizes the function of detection and setting by receiving control commands from the master. The master receives data responsing from the slave, and realizes the function of displaying and outputting the alarm signal when the gas concentration overruns.In this thesis, the infrared gas sensor, the software and hardware design of the infrared gas analyzer are designed in details.AT89C52 serves as the master and ATmega16 serves as the slave.The slave combinates external circuits of signal processing and A/D conversion to realize the gas concentration measurement, and then transfers gas concentration datas to the master through the communication interface.The displaying module of the master, which achieves the real-time displaying, and the alarming module accomplishes the sound and light alarming when the gas concentration overruns.The software based on the hardware,mainly implement the algorithm of sampling the concentration signal, calculating the value of the concentration, the real-time displaying of the values of gas concentration and setting parameters. The software also built the communications protocol between the master and the slave, which improves the reliability of the data transfering effectively.Finally, the system of gas preparation was designed, and the gas analyzer test platform was built up.The test measurement and the analysis of the test result proved that the analyzer design is reasonable, the gas concentration meet the precision that the vehicle infrared gas analyzer expect to achieve.