Research Of Absorbed Fiber-optic CO Gas Sensor Signal Processing

With the development of the oil and natural industry, the safety of energy production and the problems of environmental pollution have become the focus of people day by day. Real-time monitoring to a variety of poisonous,harmful,inflammable and explosive gas from coal production,industrial production and our daily life becomes more and more important. Compared with the traditional electric sensor, the optical fiber sensor will not produce electric spark and explode, will never being aging and poisoned. Optical fiber gas sensor can be used in that condition because it adopts optic not electricity as information carrier. Spectrum absorption fiber-optic gas sensor has very significant research and practical value due to its high sensitivity, fast response, high anti-electromagnetism interference, interesting many domestic and foreign scholars.Key technology and main components of spectrum absorption fiber-optic carbon monoxide(CO) gas sensor were studied in this article. Firstly, two kinds of weak signal processing technology, the differential absorption detection and harmonic detection were detailed analyzed, according to gas molecule absorption spectrum theory, the difference-harmonic-detection model found. Then, the gas chamber was designed, the main components, such as illuminant, photoelectric detector etc were chosen, according to design requirement of sensor system. Next, the weak light signal detection module was designed by the application of modern photoelectric detection techniques and weak signal processing technology. And then, the signal processing module was designed , with virtual instrument LabVIEW as a tool. After that, in order to verify the feasibility and practicability of this design, the experimental measurement was given, experimental results was in-depth discussed. Finally, all the work done in this design was summarized and later research direction was looked forward.