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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Měření výšky hladiny pomocí OVS / Measurement of Level by Fiber Optic Sensors

Bednář, Tomáš January 2011 (has links)
The subject of this master‘s thesis is the issue of design of fiber optic sensor for min/max and continuous measurement of liquid level, which could be used for laboratory measurement of optoelectronics. The thesis is divided into the three parts, the first part deals with methods of retrieval level measurement using fiber optic sensors. The second part is made of plant design of optical fiber sensors, it is shown the implementation of measuring devices for liquid level measurement and measured transfer characteristics of the sensors developed. The last part is proposed for laboratory typing tasks using established preparation for teaching in the subject Optoelectronic sensors.
42

METODY MĚŘENÍ ULTRAKRÁTKÝCH NEPERIODICKÝCH ELEKTROMAGNETICKÝCH IMPULSŮ / METHODS FOR MEASUREMENT OF ULTRA-SHORT SINGLE-SHOT ELECTROMAGNETIC PULSES

Drexler, Petr January 2007 (has links)
This thesis deals with the aspects of methods for pulsed high-level EM quantities measurement. Methods for current and voltage measurement in pulsed power generator and power measurement in pulse microwave generator are discussed. New approaches to single-shot measurement methods application are proposed. The theoretical analysis of suitable sensor designs is performed. The magneto-optic measurement method has been experimentally realized. On the basis of experimental results a fiber-optic current sensor has been designed and theoretically analyzed. For identification and measurement of the free-space electromagnetic pulse a combined calorimetric sensor has been designed and built.
43

Elektronski sistem za merenje deformacija pri savijanju pomoću polimernog optičkog vlakna sa osetljivom zonom / Electronic system for measurement of deformations under bending by usingpolymer optical fiber with sensitive zone

Stupar Dragan 21 April 2016 (has links)
<p>U ovoj doktorskoj disertaciji je razvijen elektronski senzorski sistem za merenje deformacija pri savijanju pomoću polimernog optičkog vlakna sa osetljivom zonom. Opisana je metoda izrade fiber-optičkog senzora zakrivljenosti pomoću polimernog optičkog vlakna. Izvršena je simulacija ponašanja senzora i urađena je karakterizacija senzora. Ispitana je mogućnost primene elektronskog senzorskog sistema za detekciju savijanja i loma građevinskih struktura. Pomoću istog senzora je realizovan fiber-optički goniometar za merenje ugla savijanja ljudskog kolena koji karakterišu linearni odziv u opsegu uglova od -45&deg; do 25&deg;, rezolucija od 1&deg; i osetljivost od 20 mV/&deg;. U tezi je takođe data metoda eliminacije grešaka koje mogu nastati usled savijanja delova vlakna koji vode do i od osetljive zone.</p> / <p>In this thesis, an electronic system for measurement of bend-induced<br />deformations by using polymer optical fiber with sensitive zone is developed.<br />A method for fabrication of the fiber-optic curvature sensor by using polymer<br />optical fiber is described. The simulation and characterization of the sensor<br />behavior have been conducted. The possibility of application of the proposed<br />electronic system in structural health monitoring for bending and crack<br />detection of civil engineering structures is investigated. Also, a fiber-optic<br />goniometer for human joint movement monitoring characterized by a linear<br />response in the range from -45&deg; to 25&deg;, resolution of 1&deg;, and the sensitivity of<br />20 mV/&deg; is implemented. A method for the elimination of errors which may be<br />caused due to bending of lead-in and lead-out sections of the fiber (leading<br />to and from the sensitive zone) is also described.</p>
44

Distributed fiber optic sensors for measuring strains of concrete, steel, and textile reinforcement

Zdanowicz, Katarzyna, Gebauer, Daniel, Speck, Kerstin, Steinbock, Oliver, Beckmann, Birgit, Marx, Steffen, Koschemann, Marc 22 April 2024 (has links)
The article describes measurements of strains of concrete, steel and textile reinforcement with distributed fiber optic sensors (DFOS). The technology of distributed strain measurements gains currently increasing attention within the civil engineering field and indeed the DFOS can be applied in various measurement scenarios providing results and insights which were not possible before. Within this article, the fibers and adhesives that are most commonly used are compared and several measurement scenarios and their results are described, including precise strain measurements with high resolution as well as measurements on large-scale specimens. Concrete strains were measured in a multiaxial compression stress state and also during setting and hardening and in flexural tests. Strains of the steel and textile reinforcement were monitored along the bond zone and also in flexural tests. Finally, cracking patterns were observed and compared with digital image correlation methods. Validated examples of applications of DFOS in laboratory work are described.
45

Contribución al desarrollo de sensores de temperatura y redes de sensores en tecnología de fibra óptica

Madruga Saavedra, Francisco Javier 06 October 2006 (has links)
Este trabajo de tesis recoge las contribuciones aportadas en el campo de los sensores de fibra óptica en tres ámbitos de trabajo. Un sistema sensor de alta temperatura sin contacto con transductores de fibras ópticas de sílice se ha presentado. Dos topologías de "ojo abierto" y "ojo cerrado" y un algoritmo de decodificación "pirometría de banda dual" propuesto en este trabajo son las novedosas aportaciones presentadas. El sistema ha sido validado en laboratorio y en pruebas de campo de forma exitosa. Para sensores de temperatura con fibras dopadas con Erbio se ha demostrado que su máxima sensibilidad tiene lugar cuando la longitud utilizada es superior a la óptima exigida por el bombeo. Finalmente se ha modelado y validado en laboratorio una red de sensores acústicos basados en interferómetros Fabry-Perot de cavidad larga determinando a partir del modelo obtenido la fase mínima detectable y la visibilidad máxima del sistema. / The thesis collects contributions in the field of optic fibre sensors for three areas. A high temperature sensor system without contact based on silica optic fibre transducers has been submitted. Two topologies "open eye" and "closed eye" and a dual band pyrometer decoding algorithm are the submitted innovative contributions. The system has been validated successful in the laboratory and field tests so. Another contribution has been the demonstration that the maximum sensitivity for temperature sensors based on Er-doped fibres occurs when the used length is more than the optimum required by pumping. Finally a network of acoustic sensors based on Fabry-Perot fibre interferometers has been modelled and validated in the laboratory. The minimum detectable phase and maximum visibility of the system has been obtained from the proposed and validated model

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