The Development And Application Of Temperature-Sensitive Fire Hazard-Alarming System Of FBG

The stability of traditional fire hazard-alarming productions is lower and its request for maintenance technology is higher. Traditional fire hazard-alarming productions are not suitable for being used in big oilcan or oleic storeroom region in petrochemicals industry, high voltage region in electrical power industry, and some special location. In the thesis, the development situation and trend of fire automatic hazard-alarming system home and abroad were investigated in detail. A new kind of temperature-sensitive fire hazard-alarming system of fiber grating was designed using the advantage of fiber grating sensor. The fire hazard-alarming system solves the disadvantage of traditional fire hazard-alarming system, and it has great practical significance.In the thesis, several demodulation projects existing of fiber grating sensor were studied, and the advantages and disadvantages of these projects were analyzed respectively. The demodulation precision with DWD and FBG as demodulation grating was compared by using MATLAB simulation. The simulation result indicated: demodulation was able to be done exactly by using DWDM as demodulation grating when there were not several reflection spectrum of different temperature sensing gratings, which arrived at demodulation grating simultaneously. But when there were several reflection spectrum of different temperature sensing gratings, which arrived at demodulation grating simultaneously, demodulation was not able to be done exactly by using DWDM as demodulation grating and could bring misinformation phenomenon. Demodulation could be done exactly by using FBG as demodulated grating and could not bring misinformation phenomenon as mentioned above. Thereby FBG was used as demodulation grating matching with demodulation project.The hardware circuit of entire system was designed and fabricated. According to the request of the system on the chip, main controlling circuit...