提出了一种基于双光纤宏弯耦合效应的新型带式漏水传感装置的整体设计方案。传感探头采用未经任何处理的双光纤扭绞螺旋结构,利用光纤宏弯时引起光纤内传播的光束泄露到双光纤扭绞结构中,并受环境折射率的调制,从而实现漏水传感。设计电路进行微弱信号提取,最后利用锁相放大技术改善信号质量,根据最后输出电压值的变化判定有无漏水及漏水量的多少。采用寻址定位法实现长达12.8 m的检测范围内50 mm的检测精度。搭建漏水检测实验平台,经实验证实,电压—漏水量关系接近线性,50 mm测量范围内最大线性误差为2.06 mm。
A overall sensing scheme of new tape leak sensors was proposed based on dual fibers macrobend coupling effect,sensing probe without any treatment of the dual twisted fiber helix structure was abdopted.By using optical fiber macrobend beam leaking to the dual twisted fiber structure and modulating by the environment refractive index,water leakage sensing was achieved.Weak signal extraction circuit was designed,and finally the lock-in amplifier technology was used to improve signal quality,the number for leaks and leakage amount of the change was judged by the final output voltage.The method of addressing positioning was used to achieve the detection range of up to 12.8 m,50 mm detection accuracy.A water leakage detection test platform was built.The experiments results confirmed that voltage-nearly linear relationship between the amount of leakage within the measuring range of50 mm maximum linearity error of 2.06 mm.