非分光红外气体传感器的光学系统和控制软件设计.pdfVIP

Abstract With the improvement of people’s living standards and the development of industry, the emissions of carbon dioxide and other pollution gases has been increased, and then the worlds temperature gradually increased. When the carbon dioxide and other gas’s concentration increased, these gases are harmful to human’s health at the same time, we need monitor the carbon dioxide polluted gas’s concentrations strictly to protect the normal life of human. Therefore, to research and design a kind of detection system to detect carbon dioxide’s concentrations has great significance. According to the Beer-Lambert law and the infrared absorption spectrum of carbon dioxide, a kind of Infrared light source and pyroelectric infrared detectors are chose to use in the design of the whole system. In practical application, the infrared absorption spectrum width is only a little nanometers while the emission spectrum of the infrared light source used in the gas sensor are not narrow-band, so the absorption spectral width is only a small part of the infrared radiation source and the gas absorption signal will be drowned in the noise. The entire sensor system is designed to be based on two wavelength differential detection principle which have two narrow band filters and one optical path to reduce even eliminate the affect caused by instability of infrared radiation source, the interference to optical chamber from environment, the temperature-drift of optoelectronic devices and pyroelectric infrared detectors noise. We also made a simulation comparison for several commonly optical chamber by using the LightTools software t