基于OTDR的光纤液体泄漏检测的研究

Research on Optical Fiber Liquid Leakage Detection Based on OTDR

通过应用光时域反射仪(OTDR)测量多模光纤(MMF)反射光强变化,提出一种检测液体泄漏的光纤传感器,并对其进行理论仿真和实验研究.文中设计了2个远距离的光纤传感器.第一个传感器仅带有1个光纤传感结构.连接带有传感结构的长光纤和OTDR.设置OTDR的扫描脉宽30 ns、扫描时间3 min,光源的脉冲信号强度约为15 d B、扫描距离5 km.以水为检测对象时,光损耗减小,反射光强度变大.实验结果和仿真结果一致;第二个传感器是由2个传感结构的分布式复用传感器,用于检测两处的环境情况.2个传感结构都能很灵敏地检测水,证明了传感器的复用特性.该液体泄漏检测光纤传感器能被广泛应用于工程实践中.

By using optical time domain reflection （OTDR） to measure the intensity of the reflected light intensity of multi-mode fiber （ MMF）, a fiber optic sensor which can detect the leakage of liquid is proposed, and the theoretical simulation and experimental study are carried on. Two sensors are designed in this paper. The first sensor is only with a sensing structure. It connects OTDR and the long fiber with the sensing structure. The scanning pulse width is set to 30 ns, the scan time of 3 min, the strength of the light pulse signal about 15 dB, the scan distance of 5 km on the OTDR. When take water as test object, the loss of OTDR is decreased, and the intensity of the refleeted light is large. The experimental results are consistent with the simulation results. The second sensor with two sensing structures is made into the distributed multiplex sensor for detecting water of different regional environment. The two sensor structures can detect water sensitively, which proves the multiplexing characteristic of the sensor. Therefore, the liquid leakage detection optical fiber sensor can be widely used in engineering practice.