Mems Infrared Gas Sensor Detection System

In company with the development of the petroleum & gas industry in the world, theleakage accident about methane increased with each passing day. It's becoming seriousproblem that how to detect the methane and fuel leakage in industrial zone & residentialarea's duct and the accumulation of methane in mine. After elaborate investigate, we findthat the methane detection equipment of our country's mine is mostly fall behind. So itsdetection area is small and its reaction time is slowly. More seriously, these detectionequipments have big body and high cost and need adjust half the time, it can't meet therequirement of detecting some harmful gas in people's daily life. In order to enhancepeople's safety monitoring ability, it's exactly need developing a new integration,miniaturization, low servicing optical gas monitoring device.Along with the development of MEMS devices,in particularly the appearance of newsemiconductor devices(infrared LED, infrared sensor)and micro-optics devices(MEMSgrating, MEMS infrared heat sensitive detector),some large infrared methane gas analyzerbecome more micromation and integration. The have many advantages, like low cost, smallbody, light weight and carry-home. Then, the infrared optical gas detection method have theacknowledged advantages that there are high detection precision, wide range, high reliability,long operating life and so on.The infrared absorption theory are expatiated in this paper, and also expatiate that howto design a two channel MEMS infrared detector using MEMS technology and integrationtechnology which based on double compensation principle and how to design a two-colormercury-cadmium-telluride detector which was used in gas detecting by a newsemiconductor refrigeration technology that combine the present research in our nation.The overall design method of infrared detection system, weak-signal detectiontechnology and system's software & hardware design are major introduced in this paper. It isalso analyze and expatiate how to use high integration mixed type chip as a microcontrollerwhich collecting multichannel data, judgment and disposal, display data and transmissionand come true some other functions. The using of microcontroller makes the system can becontrolled by a single-chip microcomputer very easy. So the system can be moremicromation and its power consumption is reduced greatly. This paper also introduced thewireless data transmission and CAN bus data transmission which used in mine and somespecial duct environment.At the end of this paper, the protective measure of coal mine gas detection system hasrecommended. Such as mine electrical equipment's explosion prevention principle,specification, explosion precaution and so on. Some dust prevention and waterproofknowledge are also recommended.The development method and principle of integrated carbon dioxide and methanesensing detection system and portable methane sensing detection system are expatiated inthis paper. Experiment and detection data argumentation are presented. Contemporary, thissuccessful research of infrared methane detector is a real contribution of Chinese coalmine.The most important is that we can detecting other gas using this method, for example,detecting some diatomic molecule gas such as CO,CO2,H2S,C2H2. It can make these gassensor come to production and widely used in coalmine gas detection, environmentalpollution detection, gas conduit detection, family's natural gas detection or other field. It willhave widely application market.