Long-term reliability of transmission loss in optical fiber cables

1988 ◽  
Vol 6 (2) ◽  
pp. 210-217 ◽  
Author(s):  
S. Tanaka ◽  
M. Honjo
Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3754 ◽  
Author(s):  
Yongji Yan ◽  
Xu Zhang ◽  
Haopeng Li ◽  
Yu Ma ◽  
Tianci Xie ◽  
...  

A novel ultraviolet (UV) optical fiber sensor (UVOFS) based on the scintillating material La2O2S:Eu has been designed, tested, and its performance compared with other scintillating materials and other conventional UV detectors. The UVOFS is based on PMMA (polymethyl methacrylate) optical fiber which includes a scintillating material. Scintillating materials provide a unique opportunity to measure UV light intensity even in the presence of strong electromagnetic interference. Five scintillating materials were compared in order to select the most appropriate one for the UVOFS. The characteristics of the sensor are reported, including a highly linear response to radiation intensity, reproducibility, temperature response, and response time (to pulsed light) based on emission from a UV source (UV fluorescence tube) centered on a wavelength of 308 nm. A direct comparison with the commercially available semiconductor-based UV sensor proves the UVOFS of this investigation shows superior performance in terms of accuracy, long-term reliability, response time and linearity.


1986 ◽  
Vol 88 ◽  
Author(s):  
M. E. Elias ◽  
A. M. Elias

ABSTRACTA new method for optical fiber production is shown. Hydrolytic polycondensation of tetramethoxysilane using a low concentration of α-picoline, 1.56×10−3% in water, gives SiO2 gel which was dried at 22 °C to a transparent amorphous material.The densification process shows an exponential time dependence with a final value of 2.253 g/cm3 after 30 days. The specific surface area of the porous gel varies from 500 to 600 m2/g but pores are eliminated by the sintering process. Before sintering the gel, it is treated under an oxidizing atmosphere above 700 °C. At 1200 °C the pores are eliminated and a solid glass rod obtained.After the sintering process a fiber is obtained from the rod which shows a transmission loss as low as 5.5 dB/km at 840nm.


Author(s):  
Daniel Dousek ◽  
Matěj Komanec ◽  
Ailing Zhong ◽  
Dmytro Suslov ◽  
Stanislav Zvánovec ◽  
...  

Author(s):  
Xin'gang LUAN ◽  
Xinming XU ◽  
Rong YU ◽  
Qiqi ZHANG ◽  
Sam ZHANG ◽  
...  

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3267 ◽  
Author(s):  
Wusheng Zhao ◽  
Kun Zhong ◽  
Weizhong Chen

A borehole deformation sensor for long-term stress monitoring in coal mine rock based on optical fiber Bragg gratings (FBGs) is presented. The sensor converts borehole deformation into optical fiber strain by using four rings. For each ring, two FBGs are bonded with the ring to measure the borehole deformation, and a reference FBG free from mechanical load is introduced to remove the temperature effect. Two simple checks on the test data can be performed to improve the test accuracy. Laboratory and field tests were conducted to validate the accuracy and long-term performance of the sensor. The results show that the sensor is capable of measuring stress in rock with good accuracy, and it performs well over a long period of time in coal mines. The developed sensor provides an approach for the long-term monitoring of stress changes in coal mine rock.


1988 ◽  
Vol 6 (2) ◽  
pp. 218-225 ◽  
Author(s):  
M. Kuwazuru ◽  
Y. Namihira ◽  
K. Mochizuki ◽  
Y. Iwamoto

2001 ◽  
Vol 124 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Shan-Tung Tu ◽  
Jian-Ming Gong ◽  
Xiang Ling ◽  
Xiao-Yuan He

Creep deformation localization is a common occurrence generally found in high temperature components, typically at weldments and geometrical discontinuities. The deformation in a small region cannot be measured by a conventional displacement gage. A new technique for measuring long-term local creep deformation was developed. It uses quartz optical fiber marking, remote monitoring, and image processing. Long-term measurements of the creep deformations of base metal, weld metal, and heat-affected zone in cross-weld specimens were performed at high temperature, which verify the new technique. Strain distributions and evolutions in the weldments are obtained.


2021 ◽  
Vol 11 (24) ◽  
pp. 12153
Author(s):  
Sung-Tae Kim ◽  
Young-Soo Park ◽  
Chul-Hwan Yoo ◽  
Soobong Shin ◽  
Young-Hwan Park

This study aims to develop a prestressed concrete steel (PC) strand with an embedded optical Fiber Bragg Grating (FBG) sensor, which has been developed by the Korea Institute of Civil Engineering and Building Technology since 2013. This new strand is manufactured by replacing the steel core of the normal PC strand with a carbon-fiber-reinforced polymer (CFRP) rod with excellent tensile strength and durability. Because this new strand is manufactured using the pultrusion method, which is a composite material manufacturing process, with an optical fiber sensor embedded in the inner center of the CFRP Rod, it ensures full composite action as well as proper function of the sensor. In this study, a creep test for maintaining a constant load and a relaxation test for maintaining a constant displacement were performed on the proposed sensor-type PC strand. Each of the two tests was conducted for more than 1000 h, and the long-term performance verification of the sensor-type PC strand was only completed by comparing the performance with that of a normal PC strand. The test specimens were fabricated by applying an optical fiber sensor-embedded PC strand, which had undergone long-term performance verification tests, to a reinforced concrete beam. Depending on whether grout was injected in the duct, the specimens were classified into composite and non-composite specimens. A hydraulic jack was used to prestress the fabricated beam specimens, and the long-term change in the prestress force was observed for more than 1600 days using the embedded optical fiber sensor. The experimental results were compared with the analytical results to determine the long-term prestress loss obtained through finite-element analysis based on various international standards.


2019 ◽  
Vol 48 (11) ◽  
pp. 1118002
Author(s):  
张景川 Zhang Jingchuan ◽  
张 雯 Zhang Wen ◽  
杨晓宁 Yang Xiaoning ◽  
裴一飞 Pei Yifei

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