基于分布式光纤的温度、振动、声音、应变的监测技术与实现

Monitoring technology and implementation of tempetature,vibration,acoustics and strain utilizing distributed optical fibers

常规的电子式传感网络多采用传感器单点布设、电信号数据传输、总线式组网的方案构建,其大多存在监测点分布分散、抗干扰性能差等缺点,不适用于长距离、大测点容量、恶劣工况等应用场合。针对上述问题,分别基于拉曼散射、瑞利散射、Sagnac干涉和布里渊散射原理,利用长距离光纤实现了温度、振动及应变的多参量分布式传感与监测,并研制了分布式光纤测温仪、测振仪、光纤麦克风和应变测试仪。测试结果表明,在10km测量距离下,温度测量精度为±1℃,空间分辨率为1.5m;在10km测量距离下,振动测量空间分辨率为20m,定位误差为8m;在10km测量距离下,光纤麦克风可实现全方向拾音;在10.8km测量距离下,应变测量精度为±56με,空间分辨率为1.15m。

Conventional electronic sensing networks are ordinarily built on the field-bus framework. In the net- work, the data are typically transmitted through electronic signals and the sensors are commonly arranged discretely. Thus,most conventional electronic sensing networks suffer from intrinsic flaws, such as too scattered monitoring points and poor anti-interferenee performance,and they are not suitable for special applications with the features of long dis- tance,large-capacity measuring points, and severe working condition. In view of above problems, distributed multi-pa- rameter sensing and monitoring by utilizing long-range optical fiber was accomplished. The measured parameters in- cluded temperature,vibration and strain, which are determined respectively based on principles of Raman scattering, Rayleigh scattering and Brillouin scattering. Besides,the prototypes for distributed temperature,vibration,strain monito- ring including an optical fiber microphone were respectively manufactured and presented. The experimental results demonstrate that： the temperature measurement accuracy is intrinsic ± 1℃ over the 10 km optical fiber with the spatial resolution of 1.5m; the vibration measurement space resolution is 20m with the positioning error of 8m over a 10 km optical fiber; the optical fiber microphone can realize all-direction acoustic sensing at the distance of 10 kin; the strain measurement accuracy is ±56με when the measured distance is 10. 8km and the spatial resolution is 1. 15m.