Clear Water Bay

ABSTRACT In order to detect methane (CH 4 ) accurately and reliably, this paper presents a sensor which consists of infrared diode, Underground the spontaneous combustion of coal, fire, electrical sparks, sparks-line locomotive, smoking and spark caused by friction, impact and blasting, can ignite CH 4 . If the oxygen content in mixture of air and CH 4 is less than 12 %, the mixture gas is not going to be explosive. In the coal mine, when CH 4 concentration is found to exceed 1%, production has to be halted, and in the condition of more than 1.5% of CH 4 concentration, all equipments are to be stopped In addition, not only does the gas pose a threat to the safety of industry and coal mine operations, but also gas leakage causing by gas pipeline corrosion of many years in the cities has become a big hidden trouble of city safety Therefore, whether it is in industry, mine or daily life, to detect CH 4 in real time is needed badly. A number of methods such as electrochemical, optical, electrical, gas chromatography methods etc. have bee