Suppression of long distance instability on remote sensing signal of pulse correlation measurement in optical fiber sensing

Optical fiber sensing has the potential to overcome weak points of traditional electric sensors. Many types of optical fiber sensors have been proposed according to the modulation parameter of incident light. We have proposed an optical pulse correlation sensing system that focuses on the time drift values of the propagating optical pulses to monitor the temperature- or strain-induced extension along the optical fiber in the sensing region. In this study, we consider the instability in the optical pulse correlation sensing system applied to remote monitoring over a kilometer-long distance. We introduce a method to stabilize the instability of the pulse correlation signal resulting from the time drift fluctuation along a transmission line. By using this method, we can purify the response and improve the accuracy of signals at the focused sensing regions. We also experimentally demonstrate remote temperature monitoring over a 30 km-long distance using a remote reference technique, and we estimate the resolution and the measurable span of the temperature variation as(1.1/L)∘Cand(5.9×10/L)°C, respectively, whereLis the length of the fiber in the sensing region.

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Long-Distance Pipeline Safety Early Warning: A Distributed Optical Fiber Sensing Semi-Supervised Learning Method

IEEE Sensors Journal ◽

10.1109/jsen.2021.3087537 ◽

2021 ◽

pp. 1-1

Author(s):

Yiyuan Yang ◽

Haifeng Zhang ◽

Yi Li

Keyword(s):

Optical Fiber ◽

Supervised Learning ◽

Early Warning ◽

Learning Method ◽

Long Distance ◽

Fiber Sensing ◽

Optical Fiber Sensing ◽

Distributed Optical Fiber ◽

Pipeline Safety

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Multi-gas leakage synchronous monitoring system based on the distributed optical fiber sensing technology

Journal of Computational Methods in Sciences and Engineering ◽

10.3233/jcm-215842 ◽

2021 ◽

pp. 1-7

Author(s):

Lu-Jun Cui ◽

Yan-Long Cao ◽

Hong-Hong Guo ◽

Shi-Rui Guo ◽

Wenhang Zeng ◽

...

Keyword(s):

Optical Fiber ◽

Monitoring System ◽

Long Distance ◽

Gas Concentration ◽

Gas Leakage ◽

Fiber Sensing ◽

Sensing Technology ◽

Optical Fiber Sensing ◽

Distributed Optical Fiber ◽

Synchronous Monitoring

In the process of long-distance transportation of different gas, the remote pipeline plays an irreplaceable role in energy transmission. When the pipeline is laid in remote areas for a long distance, it is easy to be influenced by geological disasters and complex working conditions, which may lead to corrosion and leakage. therefore, it is necessary to conduct pipeline gas real-time safety monitoring. An optical fiber gas leakage synchronous monitoring system was proposed and demonstrated based on distributed optical sensing technology for simultaneous multi-gas measurements. In this study, we discuss that the principle of multi-gas leakage synchronous monitoring system is investigated and then validated by the theoretical simulation experiments. Furthermore, gas concentration and leakage location discrimination tests are also conducted in laboratory. The experimental results show that the output intensity values increased obviously along with the gas concentration changes, and the response time of the sensor system is about 40 seconds, and it’s concluded that the multi-gas leakage synchronous monitoring system based on distributed optical fiber sensing technology exhibited good sensing and location discrimination performance.

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Application of Multiscale Fiber Optical Sensing Network Based on Brillouin and Fiber Bragg Grating Sensing Techniques on Concrete Structures

International Journal of Distributed Sensor Networks ◽

10.1155/2012/310797 ◽

2012 ◽

Vol 8 (10) ◽

pp. 310797 ◽

Cited By ~ 7

Author(s):

Xuefeng Zhao ◽

Jie Lu ◽

Ruicong Han ◽

Xianglong Kong ◽

Yanhong Wang ◽

...

Keyword(s):

Optical Fiber ◽

Fiber Bragg Grating ◽

High Sensitivity ◽

Bragg Grating ◽

Accurate Information ◽

Long Distance ◽

Fiber Sensing ◽

Sensing Technology ◽

Optical Fiber Sensing ◽

Distributed Optical Fiber

The paper reports the application of the distributed optical fiber sensing technology and the FBG sensing technology in bridge strain monitoring; the overall changeable characteristics of the whole structure can be obtained through the distributed optical fiber sensing technology (BOTDA), meanwhile the accurate information of local important parts of the structure can be obtained through the optical fiber Bragg grating sensor (FBG), which can improve the accuracy of the monitoring. FBG sensor has a high sensitivity, but it can only realize the measurement of local discrete points for the quasidistributed sensing. BOTDA can realize the long distance and distributed measurement, but its spatial resolution is not high. FBG and BOTDA were applied together in bridge monitoring in this test, taking full advantage of the distributed BOTDA on the overall strain measurements of the structure, as well as monitoring the key parts by the arrangement of FBG. The combined application of BOTDA and FBG can achieve the overall monitoring from point to line and then to the surface and, therefore, obtain more comprehensive information on the strain of the test structure.

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