Дисертації з теми "Optical fibre sensor (OFS)"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Optical fibre sensor (OFS)".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Bulur, Hatice Gonca. "Determination Of Buried Circular Cylinder With Ground Penetrating Radar Using An Optical Fiber Sensor." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613702/index.pdf.
Повний текст джерелаground-probing radar&rsquo
, &lsquo
ground penetrating radar (GPR)&rsquo
, &lsquo
sub-surface radar&rsquo
or &lsquo
surface-penetrating radar (SPR)&rsquo
refer to various techniques for detecting and imaging of subsurface objects. Among those terms GPR is preferred and used more often. In this thesis, the depth and the position of the buried circular cylinder are determined by a GPR system which comprises of an optical fiber sensor (OFS). The system is a combination of OFS, GPR and optical communication link. In order to determine the depth and the position, first of all the electric field distribution at the OFS is obtained by integrating the Green&rsquo
s function over the induced current distribution. Those distributions are observed for different frequency and depth values. The voltages inside the distribution are measured by OFS. By changing the depth of the cylinder and the frequency of the system, various plots showing x axis displacement versus measured voltages are obtained. Those plots are related to interference fringe patterns. The position and the depth of the cylinder are obtained using interference fringe patterns. All of the studies mentioned are performed in MATLAB R2007b program. The noises of the system due to OFS are extracted using OPTIWAVE OPTISYSTEM 7.0 program. By adding those noises to the measured voltage values, the operating frequency of the system is observed.
Ali, Alvarez Shamyr Sadat. "Capteurs de corrosion à fibre optique pour la surveillance répartie d’ouvrages en béton armé." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAI042.
Повний текст джерелаCorrosion of reinforced bars (rebars) in concrete structures remains a major issue in civil engineering works, being its detection and evolution a challenge for the applied research. Usual non-destructive corrosion detection methods involve impedance, potential or ultra-sonic indirect measurements of complex interpretation. Besides, they are restricted to near-surface examinations and the maintenance cost is still high (scheduled maintenance). Many efforts remain to be done to survey the onset and progression of corrosion processes in a reliable way. In this work, we present a new methodology to detect the onset of corrosion and to monitor its evolution, based on the direct observation of rebar–concrete interface changes by the use of an Optical Fiber Sensor (OFS). The corrosion attack over rebar surface depends on several physical, chemical and electrochemical parameters (temperature, pH, presence of chlorides/CO2, biological contamination, etc.). Two types of mechanical behavior and described. In the first case (carbonation), metal oxidation products stay at the interface and increase internal pressure, potentially leading to a crack of the external concrete layer. In the second case (pitting), metal ions are evacuated out of the structure, leading to a reduction of the rebar section (structural weakness). An innovative sensor design is proposed with the purpose of localizing and quantifying the amount of both corrosion types. The basic principle consists in measuring the impact of corrosion over the state of strain of a prestressed optical fiber. Two metrological techniques are used: Fiber Bragg Grating (FBG) and Optical Frequency-Domain Reflectometry (OFDR). Accelerated corrosion tests were performed in electrolytic solutions for both kinds of corrosion types (pitting and carbonation) and provide a proof-of-concept for the technique. A low-cost, simplified manufacturing procedure is proposed with the aim to provide distributed and in situ Structural Health Monitoring (SHM), suitable for future Condition-Based Maintenance (CBM) of civil engineering concrete structures
Waris, Marc. "Mise en œuvre, instrumentation, validation et modélisation d’un système d’injection RTM pour la fabrication de structures composites de hautes performances." Thesis, Saint-Etienne, EMSE, 2012. http://www.theses.fr/2012EMSE0661/document.
Повний текст джерелаA significant growth in production and consumption of composite materials can be seen recently; growth reinforced by the new European standards, aimed at reducing CO2 emissions by the year 2020.The producing of complex parts can cause many difficulties for manufacturing because of their geometries and / or their constituents (using of various materials). For example, dry zones or geometric distortion formation. The origins of these difficulties are often related to a lack of knowledge and control of the reinforcement's impregnation phases and material curing.Improving the robustness of the processes demands a detailed knowledge of physical phenomena that occur during the producing. For this, we studied the composite materials production through the implementation of a laboratory demonstrator in the project LCM Smart. This pilot injection was used to validate instrumentation solutions, from innovative sensors (OFS) developed in partnership with the optical laboratory Hubert Curien. The application of this instrumentation in the context of RTM process monitoring in the development of simple parts has demonstrated the capabilities of OFS to control physical characteristics of the part (the flow front, temperature, residual strain and curing degree). The comparison of the measured characteristics with numerical simulations carried out in collaboration with ESI showed a good correlation.Finally, instrumentation has demonstrated the capacity of composite tool made by HexTool to minimize the residual stresses due to the tool/part interaction
Allsop, Thomas David Paul. "A fibre optical strain sensor." Thesis, University of Plymouth, 1999. http://hdl.handle.net/10026.1/2779.
Повний текст джерелаLudden, Brendan Patrick. "A distributed optical fibre sensor." Thesis, University of Cambridge, 1997. https://www.repository.cam.ac.uk/handle/1810/272327.
Повний текст джерелаMoss, Steven E. "Wavelength division multiplexed optical fibre sensor networks." Thesis, Manchester Metropolitan University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334635.
Повний текст джерелаMacLean, Alistair. "A distributed fibre optic water sensor." Thesis, University of Strathclyde, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248853.
Повний текст джерелаLaufer, Jan. "Photothermal determination of optical coefficients using an optical fibre sensor." Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394370.
Повний текст джерелаMerchant, David Frank. "Optical fibre fluorimeter for online measurement." Thesis, Liverpool John Moores University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313161.
Повний текст джерелаWang, Dong Ning. "White light interferometric sensor systems." Thesis, City University London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283188.
Повний текст джерелаLiang, Yuanxin. "Respiration monitoring with a fibre optic sensor." Swinburne Research Bank, 2008. http://hdl.handle.net/1959.3/47121.
Повний текст джерелаA thesis submitted for the degree of Master of Engineering, Centre for Atom Physics an Ultra-fast Spectroscopy, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, 2008. Typescript. Bibliography: p. 143-149.
Su, Xu. "Design and Evaluation of Off-centered Core Fiber for Gas Sensing." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/99348.
Повний текст джерелаMaster of Science
Gas Sensing Has Become a Very Important and Attractive Technique Because of Its Various Applications, Such as in the Increasingly Concerning Case of Environmental Issues, Automobile Emission Detection, Natural Gas Leakage Detection, Etc. It Also Has Significant Applications in Industries, Such as Safety and Health Monitoring in Underground Mines. Among Those Sensing Areas, Fiber-optic Sensors Have Drawn Considerable Attention Because of Its Small Size, Light Weight, High Sensitivity, and Remote Sensing Capability. However, Current Fiber-optic Gas Sensing Techniques Have Several Limitations on Their Potential for Long Distance Distributed Sensing Due to Difficulties Such as High Fabrication Complexity. In This Work, a Fiber-optic Gas Sensor with Special Structure Was Designed. The Sensor Can Reduce Attenuation, Keep Mechanical Strength, and Lower Fabrication Cost. To Verify the Feasibility of the Design, Theory Analysis and Simulation Were Conducted, Which Will Be Discussed in Detail in Chapter 2. Then Two Samples with a Length of 10 Cm and 40 Cm Were Prepared and Placed in a Custom Methane Sensing System for Testing. And Their Performance Such as Sensitivity Is Investigated. In Chapter 4, Theoretical Evaluations Have Been Conducted for Multiplexed Sensors Performances Evaluation to Study the Impact Fiber Parameters on Sensing System Design. The Conclusion and Summary Are Presented in Chapter 5.
Murtaza, Ghulam. "Dual wavelength referenced intensity modulated optical fibre sensor system." Thesis, Manchester Metropolitan University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358834.
Повний текст джерелаGlomon, Lhusak. "Source based chromatic methodology for optical fibre sensor systems." Thesis, University of Liverpool, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400231.
Повний текст джерелаYang, Yatao. "Development of a distributed optical fibre pH sensor system." Thesis, Glasgow Caledonian University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321322.
Повний текст джерелаWong, Yuen Mei. "Optimising the plastic optical fibre evanescent field biofilm sensor." Thesis, Liverpool John Moores University, 2008. http://researchonline.ljmu.ac.uk/5906/.
Повний текст джерелаHu, Yiqun. "Digital Spatial Domain Multiplexing technique for optical fibre sensor arrays." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245041.
Повний текст джерелаZhang, Feng Hong. "A novel optical fibre sensor based on inter-fibre distributed coupling for particle concentration measurement." Thesis, Liverpool John Moores University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361510.
Повний текст джерелаWang, Qi. "Studies of multimode fibre linked white light interferometric sensor systems." Thesis, City University London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389649.
Повний текст джерелаShen, Yonghang. "Characterization of optical fibre sensor systems for applications at high temperatures." Thesis, City University London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421643.
Повний текст джерелаRadi, Haidar M. "Frequency hopping spread spectrum multiplexing for interferometric optical fibre sensor networks." Thesis, Manchester Metropolitan University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387483.
Повний текст джерелаMasoudi, Ali. "Design and application of a distributed optical fibre dynamic strain sensor." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/375125/.
Повний текст джерелаLiu, Chen. "Advanced optical fibre grating sensors for biochemical applications." Thesis, Bangor University, 2019. https://research.bangor.ac.uk/portal/en/theses/advanced-optical-fibre-grating-sensors-for-biochemical-applications(29757d94-bfe1-4d75-a4db-8563be1a056f).html.
Повний текст джерелаLewin, A. C. "An investigation of optical fibre interferometric vibration and rotation measurement techniques." Thesis, University of Kent, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383750.
Повний текст джерелаFouchal, Farid. "Composite cure assessment using spectral analysis (via an embedded optical fibre sensor)." Thesis, De Montfort University, 2001. http://hdl.handle.net/2086/4302.
Повний текст джерелаMarshall, Raymond Hugh. "A study of optical-fibre electronically-scanned white light interferometric sensor systems." Thesis, City University London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266372.
Повний текст джерелаCheevers, Kevin. "Optical Fibre-Based Hydrophone and Critical Ignition in Detonation Cells." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42793.
Повний текст джерелаBashour, Rami. "High voltage optical fibre sensor for use in wire relay electrical protection systems." Thesis, University of Derby, 2016. http://hdl.handle.net/10545/621343.
Повний текст джерелаCusworth, S. D. "An extrinsic optical fibre sensor system for the measurement of pressure and temperature." Thesis, Manchester Metropolitan University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370938.
Повний текст джерелаHayes, Simon Antony. "Development of a reinforcing fibre light-guide for use as a damage sensor within composite structures." Thesis, Brunel University, 1995. http://bura.brunel.ac.uk/handle/2438/7119.
Повний текст джерелаZheng, Gang. "Development of advanced birefringent fibre force sensor systems based on frequency modulation continuous wave (FMCW) technology." Thesis, Glasgow Caledonian University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337411.
Повний текст джерелаDonlagicÌ, Denis. "Microbend sensor structure based on selective excitation and filtering of the modes in graded index optical fibres." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248635.
Повний текст джерелаTu, Minh Hieu. "Investigation of metal nanomaterials as a sensing element in LSPR-based optical fibre sensor development." Thesis, City University London, 2014. http://openaccess.city.ac.uk/5919/.
Повний текст джерелаAzzi, Victor, and Victor Azzi. ""Sensor-in-fibre" optical probes for molecular sensing in the gastrointestinal tract of murine models." Master's thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/37631.
Повний текст джерелаL’obésité et les maladies cardiométaboliques sont des problèmes de santé publique dans les populations nordiques du Canada ainsi qu’à travers le monde. Il est actuellement proposé que l’augmentation de ces désordres est en partie causée par divers facteurs environnementaux qui génèrent des changements importants du microbiote intestinal. Cette communauté microbienne qui peuple notre tractus gastrointestinal joue un rôle clé dans le métabolisme de nutriments, mais peut aussi avoir des effets néfastes lorsque son équilibre avec l’hôte est perturbé. Cette compréhension a mis en évidence le manque d’outils prédictifs permettant un diagnostic rapide et efficace dans le domaine biomédical. L’analyse actuelle du microbiote est réalisée à posteriori au niveau des selles, ce qui requiert du personnel hautement qualifié de même que des procédures longues et dispendieuses. L’objectif de ce projet est de concevoir un capteur optique qui, une fois implanté dans l’intestin, permettra de détecter en temps réel des biomarqueurs clés produit par le microbiome intestinal. Dans le cadre d’une preuve de concept, une architecture fibrée simple permettant de mesurer quantitativement des variations de pH est démontrée. Contrairement aux capteurs fibrés traditionnels, la sonde optique de ce projet exploite l’onde évanescente générée sur la périphérie de l’interface pour exciter des nanomatériaux greffés dont les propriétés de fluorescence varient selon leur environnement chimique. Les mesures sont possibles grâce à un système optique mobile contrôlé par un logiciel convivial qui permet à un utilisateur nonexpert d’utiliser l’appareil. Les résultats confirment qu’avec un étalonnage préalable il est possible avec cette sonde modèle de prendre des mesures quantitatives du pH en temps réel in vitro. Les expériences préliminaires suggèrent que la sonde permet aussi de mesurer le pH en temps réel dans l’intestin in vivo.
Obesity and cardiometabolic diseases (CMD) are major public health issues among Canada’s northern population and throughout the world. It is believed that the exponential rise in CMD incidence is due to numerous environmental factors, which are driving important changes in the gut microbiome. This microbial community which populates our intestinal tract plays a key role in nutrient and energy metabolism, but can also drive pathogenic mechanisms when its interaction with the host is disrupted. This understanding has highlighted the lack of predictive tools and biomarkers for rapid and efficient diagnostic of various diseases within the medical field. Current analysis of the gut microbiota is mostly based on sequencing technologies to determine microbial composition and gene expression, while functional analyses are limited to surrogate markers of microbial activities through stool metabolites. The goal of this study is to develop a “Sensor-in-Fibre” probe with the capacity to detect key microbiome-derived molecules relevant to CMD pathogenesis in real time in vivo. The optical probe takes advantage of evanescent fields generated on its peripheral interface to excite species-selective surface-grafted sensing nanomaterials that have varying fluorescent properties based on the target molecules present in the surrounding environment. As a model system, FITC functionalized with (3-aminopropyl)triethoxysilane was grafted on the periphery of an optical fiber, leading to qualitative pH measurements revealed through fluorescence emission qualities. These measurements are possible due to the use of a mobile signal collection apparatus in conjunction with custom software made to enable a non-expert technician to use it. The experimental results demonstrate that, with the appropriate preparation, it is possible to quantitatively measure pH with this probe structure in vitro and preliminary studies suggest that the probe is also capable of measuring pH in vivo in real time.
Obesity and cardiometabolic diseases (CMD) are major public health issues among Canada’s northern population and throughout the world. It is believed that the exponential rise in CMD incidence is due to numerous environmental factors, which are driving important changes in the gut microbiome. This microbial community which populates our intestinal tract plays a key role in nutrient and energy metabolism, but can also drive pathogenic mechanisms when its interaction with the host is disrupted. This understanding has highlighted the lack of predictive tools and biomarkers for rapid and efficient diagnostic of various diseases within the medical field. Current analysis of the gut microbiota is mostly based on sequencing technologies to determine microbial composition and gene expression, while functional analyses are limited to surrogate markers of microbial activities through stool metabolites. The goal of this study is to develop a “Sensor-in-Fibre” probe with the capacity to detect key microbiome-derived molecules relevant to CMD pathogenesis in real time in vivo. The optical probe takes advantage of evanescent fields generated on its peripheral interface to excite species-selective surface-grafted sensing nanomaterials that have varying fluorescent properties based on the target molecules present in the surrounding environment. As a model system, FITC functionalized with (3-aminopropyl)triethoxysilane was grafted on the periphery of an optical fiber, leading to qualitative pH measurements revealed through fluorescence emission qualities. These measurements are possible due to the use of a mobile signal collection apparatus in conjunction with custom software made to enable a non-expert technician to use it. The experimental results demonstrate that, with the appropriate preparation, it is possible to quantitatively measure pH with this probe structure in vitro and preliminary studies suggest that the probe is also capable of measuring pH in vivo in real time.
Résumé en espagnol
Résumé en espagnol
Sargeant, Ramon Bradley. "A multi-axial optical fibre and linear polarizer based force and torque sensor for dexterous robotic fingertips." Thesis, King's College London (University of London), 2014. http://kclpure.kcl.ac.uk/portal/en/theses/a-multiaxial-optical-fibre-and-linear-polarizer-based-force-and-torque-sensor-for-dexterous-robotic-fingertips(a9c419a3-901e-4a56-9b02-00648539d17e).html.
Повний текст джерелаMalki, Abdelrafik. "Capteurs de vibrations mécaniques et de pression à fibre optique." Châtenay-Malabry, Ecole centrale de Paris, 1993. http://www.theses.fr/1993ECAP0582.
Повний текст джерелаJason, Johan. "Fibre-Optic Displacement and Temperature Sensing Using Coupling Based Intensity Modulation and Polarisation Modulation Techniques." Doctoral thesis, Mittuniversitetet, Avdelningen för elektronikkonstruktion, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-18964.
Повний текст джерелаFiberoptiska sensorer används för mätning av ett antal olika fysikaliska parametrar eller för händelsedetektering i larm- och säkerhetssystem. I miljöer med elektromagnetiska störningar, i andra besvärliga miljöer där elektronik inte fungerar samt i tillämpningar där distribuerade sensorer är att föredra, har fiberoptiska lösningar funnit naturliga applikationer. I vissa fall har de ersatt konventionella elektroniska sensorer på grund av bättre prestanda och tillförlitlighet, medan de i andra sammanhang har haft mindre framgång huvudsakligen på grund av den i många fall högre kostnaden för fiberoptiska sensorsystem. Intensitetsmodulerade fiberoptiska sensorer kräver normalt endast billiga utläsningssystem huvudsakligen baserade på lysdioder och fotodioder. Principen för sådana sensorer baserade på koppling mellan fibrer är mycket enkel, och denna typ av sensorer har haft tillämpningar under en lång tid, främst inom mätning av positionsförändring och vibrationer. För distribuerade intensitetsmodulerade sensorer har system baserade på optisk tidsdomän-reflektometer (OTDR) och skräddarsydda sensorkablar funnit tillämpningar i detektion av värme/brand, vattenläckage och kolvätebaserade vätskor. I denna avhandling presenteras, simuleras, testas och utvärderas praktiskt några nya koncept för kopplingsbaserade intensitetsmodulerade fiberoptiska sensorer. Från ett lågkostnads- och standardkomponentperspektiv föreslås och analyseras alternativa lösningar för förbättrad prestanda. Utveckling och installation av en temperatursensor för en industriell tillämpning, innehållande aspekter på sensormultiplexering och nätverksbyggande, behandlas. OTDR-teknik används som en effektiv metod för multiplexering av flera kopplingsbaserade sensorer, och installation av sensornätverk genom användning av blåsfiberteknik och mikrodukter föreslås som ett flexibelt och kostnadseffektivt alternativ till traditionell kabelinstallation. Som en lösning på förekommande upplinjeringsproblem för kopplingsbaserade sensorer, föreslås en ny sensorkonfiguration baserad på koppling mellan en fiber och en multikärnefiber/fiberarray och med ett bildsensorsystem för detektering. Med detta koncept kan ett högpresterande, upplinjeringsfritt sensorsystem med ett stort mätområde åstadkommas. Sensorsystemets prestanda har analyserats teoretiskt med kompletta systemsimuleringar, och en experimentell uppställning baserad på standardfiber och en kamera av standardtyp har gjorts. Simuleringar av möjliga felbidrag visar att systemets experimentella prestanda främst begränsas av skillnader mellan den modellerade och den verkliga optiska effektfördelningen. En förbättrad modell för effektfördelningen föreslås och utvärderas experimentellt. Det visas att prestanda är möjlig att förbättra ner mot den teoretiska gräns på 1 μm som erhållits vid systemsimuleringar. Möjligheterna att använda fyllda hålfibrer och polarisationskänslig mätning för detektering av temperaturgränser studeras i syfte att komplettera befintliga fiberoptiska värmedetektorsystem. Förändringen i fiberns dubbelbrytning vid övergångstemperaturen mellan vätske- och fast fas för ämnet i hålen visas och bestäms experimentellt för hålfibrer fyllda med vattenlösningar respektive en metallegering, och resultaten understöds också av simuleringar. En punktsensor för temperaturdetektering baserad på denna princip föreslås. Vidare visas principerna för distribuerad detektering genom registrering av förändringen i dubbelbrytning med polarisations-OTDR (POTDR). Det visas att OTDR-teknik med hög spatial upplösning behövs för övervakning av de studerade fibrerna, och hålfibrer utformade med lägre dubbelbrytning föreslås för framtida studier av tillämpningen.
Crosby, Peter. "In-situ cure monitoring of epoxy resin systems." Thesis, Brunel University, 1998. http://bura.brunel.ac.uk/handle/2438/5425.
Повний текст джерелаDias, João Miguel Serras. "Monitorização remota com sensores de fibra ótica." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17319.
Повний текст джерелаEsta dissertação tem como objetivo a implementação de um sistema de monitorização remota com sensores óticos, nomeadamente sensores em redes de Bragg em fibra ótica. Foi desenvolvido um sistema de monitorização remota, baseado num acelerómetro ótico, que foi implementado no reservatório de água da Universidade de Aveiro, com sensibilidades 87,848 pm/G e 92,351 pm/G nas direções transversal e longitudinal, respetivamente. A estrutura a monitorizar é descrita fisicamente e matematicamente, através de modelos numéricos, com o objetivo de estimar a sua frequência natural segundo a direção longitudinal e transversal. É implementado e descrito um sistema de monitorização remota que consiste na ligação por fibra ótica da estrutura ao sistema central, instalado no Instituto de Telecomunicações – Pólo de Aveiro, o qual é acessível de qualquer local com acesso à internet. Foi também desenvolvido um sensor de nível para futura implementação na mesma estrutura. Estão também descritas e caracterizadas, térmica e mecanicamente, três versões do sensor de nível, que foi sendo otimizado neste trabalho. A última versão apresenta uma sensibilidade de 72,4±0,100 pm/m, entre 0 e 1 m, e uma resolução de 6,9 cm utilizando um interrogador com 5 pm de resolução. Por fim, a estrutura em estudo foi monitorizada por um período de tempo, observando-se as suas frequências naturais. Verifica-se que não existem alterações significativas do valor das frequências naturais, concluindo-se que a estrutura se encontra em bom estado, mantendo as suas propriedades físicas, nomeadamente a sua rigidez. Este trabalho demonstrou a exequibilidade de utilizar sensores óticos interligados com redes de comunicação por fibras óticas em aplicações de monitorização remota.
This dissertation aims the implementation of a remote monitoring system based on optical sensors, namely fibre Bragg grating based sensors. A remote monitoring system, based on an optical accelerometer, was developed and implemented, at the Aveiro University water reservoir, with a sensibility of 87,848 pm/G and 92,351 pm/G for the transversal and longitudinal directions, respectively. The structure to monitor is physically and mathematically described, through numeric models, with the purpose of estimate its natural frequency on the longitudinal and transversal directions. It is implemented and described a remote monitoring system consisting of an optical fibre connection of the structure to the central system, installed at the Instituto de Telecomunicações – Pólo de Aveiro, which can be accessed from any place with an internet connection. A liquid level sensor for future implementation on the same structure was developed. It is also described and characterized, thermal and mechanically, three versions of the liquid level sensor, which has been optimized during this work. The last version has a sensibility of 72,4±0,100 pm/m, between 0 e 1 m, and a resolution of 6,9 cm using an interrogator with a 5 pm resolution. At last, the structure natural frequencies were monitored over a time period. It is verified that there are no significant changes on the value of the natural frequencies, concluding that the structure is at a healthy state, maintaining its physical properties, namely its rigidity. This work demonstrated the successful use of optical sensors interconnected with optical fibre communication networks for remote monitoring applications.
Sim, Lay M. "Design, manufacturing and testing of smart beams with EFPI strain sensor for damage detection." Thesis, Loughborough University, 2003. https://dspace.lboro.ac.uk/2134/13207.
Повний текст джерелаBelhadj, Miled Othman. "Contribution a l'etude du couplage elasto-optique dans une fibre optique en vue d'une application capteur." Paris 6, 1988. http://www.theses.fr/1988PA066054.
Повний текст джерелаLyöri, V. (Veijo). "Structural monitoring with fibre-optic sensors using the pulsed time-of-flight method and other measurement techniques." Doctoral thesis, University of Oulu, 2007. http://urn.fi/urn:isbn:9789514287022.
Повний текст джерелаMahieuxe, Bruno. "Capteurs à fibre optique pour le dosage des nitrates." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL046N.
Повний текст джерелаVošček, Jakub. "Optické vlákno jako distribuovaný teplotní senzor." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-433164.
Повний текст джерелаLecomte, Pierre. "Mesure haute température en environnement irradié par fibre optique utilisant l’effet Raman." Thesis, Perpignan, 2017. http://www.theses.fr/2017PERP0067/document.
Повний текст джерелаEDF is working on Raman distributed temperature sensing using optical fiber sensors in order to map temperature of nuclear power plants big components. The sensor has to sustain harsh environmental conditions (temperatures up to 350 °C and gamma ionizing radiations). Ionizing radiations can create structural defects inside the fiber’s core, which attenuate the light transmission. This phenomenon can lead to temperature measurements errors until no measurement is possible. As for high temperature, it can affect the fiber coating, which mitigate the fiber mechanical resistance.Gamma rays in situ irradiations have been carried out over commercial off-the-shelf multimode gold coated fibers protected with a stainless steel metal tubing, with two different radiation sources, in order to observe radiation-induced attenuation over dose rate or cumulated dose. Effects of gamma rays over gold coated optical fiber sensors have been observed at both room anhigh temperature.This experimental work enlightens that high temperature can be controlled with gold coated fibers, and that the radiation-induced attenuation downsides can efficiently be balanced with high temperature. Implementation of a Raman distributed temperature optical fiber sensor in such harsh environments becomes possible, as well as the associated estimation of measurement uncertainty
Buchoud, Edouard. "Détection, localisation et quantification de déplacements par capteurs à fibre optique." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENU021/document.
Повний текст джерелаFor structural health monitoring, optical fiber sensors are mostly used thanks their capacity to provide distributed measurements. Based on the principle of Brillouin scattering, optical fiber sensors measure Brillouin frequency profile, sensitive to strain and temperature into the optical fiber, with a meter spatial resolution over several kilometers. The first problem is to obtain a centimeter spatial resolution with the same sensing length. To solve it, source separation, deconvolution and resolution of inverse problem methodologies are used. Then, the athermal strain into the structure is searched. Several algorithms based on adaptative filter are tested to correct the thermal effect on strain measurements. Finally, several methods are developed to quantify structure displacements from the athermal strain measurements. They have been tested on simulated and controlled-conditions data
Yi, Duo. "Intégration de capteurs à fibre optique par projection thermique pour des applications de contrôle de structures intelligentes." Thesis, Belfort-Montbéliard, 2016. http://www.theses.fr/2016BELF0285/document.
Повний текст джерелаThis paper presents the modeling, simulation, experimentation and design of a smart composite structrure for high temperature measurements (up to 300 °C). In order to achieve this goal, a high temperature resistant metal coated optical fiber was considered and integrated into alumina coating. The smart composite structure consists of a substrate, a coating and an intensity modulated optical fiber temperature sensor. Firstly, an estimation of heat flux based on a experimental thermogram was firstly carried out in order to feed a numerical modeling. Then, different modelings were built to evaluate the surface temperature levels as well as the composite stress levels. The simulation showed that the composite (substrate and coating) could be considered as a thermally thin medium, the heat propagation within the composite was fast and could be estimated at a scale of millisecond. The stresses remained relatively uniform during the heating process but intensified during the cooling process. The modeling also showed that the stresses are not symmetrical in the fiber and depend on the position of the fiber relative to the substrate. After a modeling evaluation of the thermal levels as well as the stresses that may be achieved in the composite, an experimental step integrating a optical fiber into a thermal coating was carried out. Microscopic observation of surface and cross section were conducted in order to analyze the characteristics of the integrated fiber. The mechanical strength of the integrated fiber was then measured and the optical attenuation during the integration process as well as the thermal behavior of the integrated fiber during the thermal cycling were evaluated. Finally, an intensity modulated optical fiber temperature sensor was designed and integrated into ceramic coating by thermal spraying. A temperature measuring system was designed and the first tests of the thermal response as well as thermal cycling of temperature sensor were carried out. This study demonstrates the feasibility of designing a high temperature resistant smart composite structure by integrating an intensity modulated optical fiber temperature sensor in a ceramic coating elaborated by thermal spraying
Morana, Adriana. "Gamma-rays and neutrons effects on optical fibers and Bragg gratings for temperature sensors." Phd thesis, Université Jean Monnet - Saint-Etienne, 2013. http://tel.archives-ouvertes.fr/tel-01064993.
Повний текст джерелаHenault, Jean-Marie. "Approche méthodologique pour l’évaluation des performances et de la durabilité des systèmes de mesure répartie de déformation : application à un câble à fibre optique noyé dans le béton." Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1113/document.
Повний текст джерелаStructural Health Monitoring is a key factor in life-cycle management of civil structures. Truly distributed fiber optic sensors, composed by an optoelectronic device paired with an optical fiber in a cable, provide strain profiles over several kilometers with a centimeter resolution. They are thus able to provide relevant information on large structures. However, a preliminary performance assessment is required prior to any industrial application. Due to shear deformation of the cable's protective coating, strain measurements provided by the measuring system may differ from actual strains in the embedding medium. A methodology, based on mechanical tests and modelling, was thus developed to determine the relationship between measured/actual strains. It was applied to determine the mechanical response of a specific cable embedded in concrete. Performance assessment method was applied to a specific measuring system. Tests were carried out under laboratory conditions on the fiber optic cable, out of the concrete medium in a first stage, and then embedded in concrete structures. It enabled to evaluate its components and standard uncertainties. The cable could not be replaced after being embedded in concrete. It is necessary to evaluate the ageing effects on its mechanical properties to use it for a long term period. A specific study was carried out to determine the cable durability under chemical, thermal and mechanical solicitations
Ronot-Trioli, Catherine. "Etude de polymères spécifiques pour la détection du méthane et de vapeurs chimiques à l'aide d'un capteur intrinsèque à fibre optique." Saint-Etienne, 1993. http://www.theses.fr/1993STET4018.
Повний текст джерела