scholarly journals Protection and Installation of FBG Strain Sensor in Deep Boreholes for Subsurface Faults Behavior Monitoring

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5170
Author(s):  
Sang-Jin Choi ◽  
Kwon Gyu Park ◽  
Chan Park ◽  
Changhyun Lee
Keyword(s):  
Strain Sensors ◽  
Load Test ◽  
Protective Measures ◽  
Sensor Performance ◽  
Uniaxial Load ◽  
Behavior Monitoring ◽  
Reinforced Plastic ◽  
Fbg Sensors ◽  
And Performance ◽  
Deep Boreholes

Fiber optic sensors are gradually replacing electrical sensors in geotechnical applications owing to their immunity to electrical interference, durability, and cost-effectiveness. However, additional protective measures are required to prevent loss of functionality due to damage to the sensors, cables, or connection parts (splices and/or connectors) during installation and completion processes in borehole applications. We introduce two cases of installing fiber Bragg grating (FBG) strain sensors in 1 km boreholes to monitor the behavior of deep subsurface faults. We present our fiber-reinforced plastic (FRP) forming schemes to protect sensors and splices. We also present uniaxial load test and post-completion monitoring results for assessing the effects and performance of the protective measures. The uniaxial load test and post-completion monitoring show that FBG sensors are well protected by FRP forming without significant impact on sensor performance itself and that they are successfully installed in deep boreholes. In addition to summarizing our learning from experiences, we also suggest several points for consideration to improve the applicability of FBG sensors in borehole environment of the geotechnical field.

758 Fabrication and performance of piezoelectric strain sensors made from PVDF/MWNT nanocomposites

2012 ◽  
Vol 2012 (0) ◽  
pp. 204-205
Author(s):  
Keisuke TANABE ◽  
Ning HU ◽  
Hisao HUKUNAGA ◽  
Satoshi ATOBE ◽  
Yutaka ZENBA
Keyword(s):  
Strain Sensors ◽  
Piezoelectric Strain ◽  
And Performance

scholarly journals Comparison between point and long-gage FBG-based strain sensors during a railway bridge load test

Strain ◽  
2017 ◽  
Vol 53 (4) ◽  
pp. e12230 ◽  
Author(s):  
B. Torres Górriz ◽  
P. Rinaudo ◽  
P. A. Calderón García
Keyword(s):  
Strain Sensors ◽  
Load Test ◽  
Railway Bridge

Design, Construction and Performance Evaluation of a Low Cost Electric Arc Welding Machine

2009 ◽  
Vol 62-64 ◽  
pp. 135-140
Author(s):  
S.O. Igbinovia ◽  
M.C. Onuoha ◽  
O.K. Olaogun
Keyword(s):  
Arc Welding ◽  
Low Cost ◽  
Short Circuit ◽  
Electric Arc ◽  
Load Test ◽  
Welding Machine ◽  
Short Circuit Test ◽  
Operating Current ◽  
Electric Arc Welding ◽  
And Performance

Apart from woodwork, brickwork, all other formworks are of metalwork. Thus engineering devices, equipment, machineries and infrastructures are made possible with the use of welding machines, be it carbide or arc – welding type. In Nigeria, where the cost of imported goods rises astronomically in accordance with the foreign exchange rates, the need to fabricate this very important equipment became of important necessity. In this paper, a single-phase 6KVA, 240VAC/30-70 VDC electric arc welding machine was designed and constructed using locally available materials. The different operating current required, arcing time, the heat generated by the arc, the minimum arc gap, the fluxite coated electrode, oxidation of the molten materials by the surrounding air where some of the designed parameters that determined the auto-transformer specific magnetic loading and specific electric loading. Cooling medium, integral switch, the rectifier circuits and the tanking of the transformer designed determined the equipment production. The locally fabricated AC/DC air cooled electric arc welding machine capable of withstanding 200A, when subjected to insulation resistance test, no – load test, short circuit test and on-load test to ascertain its performance characteristics were very satisfactory.

scholarly journals Development and Characterization of Integrated Nano-Sensors for Organic Residues and pH Field Detection

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5842
Author(s):  
Itamar Chajanovsky ◽  
Sarah Cohen ◽  
Giorgi Shtenberg ◽  
Ran Yosef Suckeveriene
Keyword(s):  
Limit Of Detection ◽  
Conductive Polymer ◽  
Organic Residue ◽  
Sensor Performance ◽  
Residue Detection ◽  
Thin Film Sensors ◽  
Nano Sensors ◽  
Emulsion Polymerizations ◽  
And Performance

Meeting global water quality standards is a real challenge to ensure that food crops and livestock are fit for consumption, as well as for human health in general. A major hurdle affecting the detection of pollutants in water reservoirs is the lapse of time between the sampling moment and the availability of the laboratory-based results. Here, we report the preparation, characterization, and performance assessment of an innovative sensor for the rapid detection of organic residue levels and pH in water samples. The sensor is based on carbonaceous nanomaterials (CNMs) coated with an intrinsically conductive polymer, polyaniline (PANI). Inverse emulsion polymerizations of aniline in the presence of carbon nanotubes (CNTs) or graphene were prepared and confirmed by thermogravimetric analysis and high-resolution scanning electron microscopy. Aminophenol and phenol were used as proxies for organic residue detection. The PANI/CNM nanocomposites were used to fabricate thin-film sensors. Of all the CNMs, the smallest limit of detection (LOD) was achieved for multi-walled CNT (MWCNT) with a LOD of 9.6 ppb for aminophenol and a very high linearity of 0.997, with an average sensitivity of 2.3 kΩ/pH at an acid pH. This high sensor performance can be attributed to the high homogeneity of the PANI coating on the MWCNT surface.

scholarly journals Fibre Bragg Grating Based Strain Sensors: Review of Technology and Applications

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3115 ◽  
Author(s):  
Carlo Campanella ◽  
Antonello Cuccovillo ◽  
Clarissa Campanella ◽  
Abdulkadir Yurt ◽  
Vittorio Passaro
Keyword(s):  
Research Field ◽  
Strain Sensors ◽  
Bragg Grating ◽  
Fibre Bragg Grating ◽  
Mode Splitting ◽  
Key Sectors ◽  
Low Costs ◽  
And Performance ◽  
Physical Principles ◽  
Advanced Applications

Fibre Bragg grating (FBG) strain sensors are not only a very well-established research field, but they are also acquiring a bigger market share due to their sensitivity and low costs. In this paper we review FBG strain sensors with high focus on the underlying physical principles, the interrogation, and the read-out techniques. Particular emphasis is given to recent advances in highly-performing, single head FBG, a category FBG strain sensors belong to. Different sensing schemes are described, including FBG strain sensors based on mode splitting. Their operation principle and performance are reported and compared with the conventional architectures. In conclusion, some advanced applications and key sectors the global fibre-optic strain sensors market are envisaged, as well as the main market players acting in this field.

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