Analysis And Study On The Test Of Motor Vehicle Exhaust Discharge

Now the pollution of the automotive exhaust is getting worse and the standard for detecting the exhaust is becoming more rigid, such as vapour, O₂, H₂, N₂, CO₂, CO, HC, NO_X, SO₂, particle, etc. Especially, CO₂, CO, HC, NO_X, SO₂, particle material are harmful to human health andnatural environment. It has been become a serious social problem.It is a worldwide environmental protection project to treat the automotive exhaust. It propels the revolution of automotive industry and the development of related industry, such as fuel, purificatory technology and monitor device. In common method of gas analysis, the infrared ray optics absorbable apparatus has been widely used in the world because it has high precision and sensitivity, fast response, large measure range, good selectivity and stability and reliability, rapid and continuous detection.The aim of the text is to eliminating the effect of environmental interference and improving the accuracy of detection and friendly interface for user operating. And the user can evaluate the technical status of engine, in particular, fuel supply system and ignition system. Aim at the problem occurred in automotive infrared analysis apparatus, targeting at the engineering application, the project has done the work as follows:The first, analog signal acquisition and A/D transition, During the data collection, the outside interference brings on inaccurate test results. The article has analyzed the environmental impact aimed at outside interference. The environment includes temperature, pressure, humidity, etc: The second is the impact of environment. The article further used the test data to confirm the result of exhaust test is different, under the different temperature and pressure: The third, using automotive exhaust sampling device to put the exhaust into device, then the infrared sensor produces the analog signal while the exhaust passes through the gas chamber. As the analog signal value produced directly from the sensor is less and is accompanied with interference signal, it must be amplified and anti-interference work must be done also. After the signal has been processed, then sent to A/D transition device and the right digit can be gotten: The fourth is the calculation of various parameters. Different parameters adopt different formula to calculate and use the compensation way not the same according to the influence of signal against environment, and the final right, accurate data can be found.