一种光纤光栅传感实验仪的可靠性分析

光纤光栅作为一种传感单元可以测试应变、温度和压力等物理量.近年来,可用于光纤光栅信号解调的技术和仪器相继出现,并在不同的场合得到了很好的应用.但由于制造、安装和操作等原因,这些仪器的可靠性问题也开始引起不同程度的关注.仪器的可靠性分析是其设计过程中不可缺少的重要环节之一.以一种基于匹配解调技术的准分布式光纤光栅解调仪为例,介绍了该仪器的基本组成和原理;采用故障树法从机械和光电器件的可能出现的如光纤光栅脆断、螺钉松动和脱焊等故障和失效形式出发,根据光路配置、电路以及机械结构分析了可能的故障模式,计算了可靠性.结论有利于对这类仪器的故障诊断和维护.

Reliability analysis of an interrogation instrument for optical fiber Bragg grating sensing

Fiber Bragg grating sensor(FBGs) can be used to measure many variables inculding strain,temperature,and pressure. Different interrogation devices are implemented to demodulate these signals from FBGs,where the original information is comprised. These devices are used for various purposes under varying conditions. The reliability problem may arise in the fabrication, installation and operations of FBGs and attracts more and more attentions.The design of reliable instrumentation calls for a regular assessment of the system reliability as the design proceeds.A quasi-distributed fiber Bragg grating sensor (FBGs) demodulation instrument based on wavelength-matched FBG has been developed especially to serve as technical training tool mainly for stain measurement. This paper is divided into two parts. Part I introduces the function and operation principles of the instrument. Part Ⅱ presents fault tree analysis (FTA) such as mechanical break of FBG,screw and weld loose during instrument usage. Possible failure modes are examined according to different optical path configurations.