TY - JOUR A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Krebber, Katerina T1 - Incoherent optical frequency domain reflectometry and distributed strain detection in polymer optical fibers N2 - We present, to our knowledge for the first time, the possibility of measuring the backscatter signal of perfluorinated polymer optical fibers (POF) using an incoherent optical frequency domain reflectometry (OFDR) technique. The OFDR setup is described and it is shown that the dynamic range and measurement speed are superior to standard OTDR systems. It is shown for the first time that distributed detection of strain in POF is possible using the OFDR technique. KW - Optical frequency domain reflectometry KW - OFDR KW - OTdr KW - Polymer optical fibers KW - POF KW - Fiber sensors KW - Distributed sensors KW - Strain sensors PY - 2010 DO - https://doi.org/10.1088/0957-0233/21/1/017001 SN - 0957-0233 SN - 1361-6501 VL - 21 IS - 1 SP - 017001-1 - 017001-4 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-21625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - A novel technique for quasi-distributed and dynamic length change measurement in optical fibers N2 - We present a novel technique to measure length changes between multiple reflection points in optical fibers. The technique allows for dynamic measurement up to 1kHz and a resolution better than 1µm. T2 - International conference "Optical sensors" CY - Karlsruhe, Germany DA - 2010-06-21 PY - 2010 DO - https://doi.org/10.1364/SENSORS.2010.STuB5 IS - STuB5 SP - 1 EP - 2 AN - OPUS4-21626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Wendt, Mario A1 - Wosniok, Aleksander T1 - Protection of critical infrastructure using fiber optic sensors embedded in technical textiles N2 - Terrorists and criminals more and more attack and destroy important infrastructures like routes, railways, bridges, tunnels, dikes and dams, important buildings. Therefore, reliable on-line and long-term monitoring systems are required to protect such critical infrastructures. Fiber optic sensors are well-suited for that. They can be installed over many kilometers and are able to measure continuously distributed strain, pressure, temperature and further mechanical and physical quantities. The very tiny optical fibers can be integrated into structures and materials and can provide information about any significant changes or damages of the structures. These so-called smart materials and smart structures are able to monitor itself or its environment. Particularly smart technical textiles with embedded fiber optic sensors have become very attractive because of their high importance for the structural health monitoring of geotechnical and masonry infrastructures. Such textiles are usually used for reinforcement of the structures; the embedded fiber optic sensors provide information about the condition of the structures and detect the presence of any damages and destructions in real time. Thus, critical infrastructures can be preventively protected. The paper will introduce this innovative field and will present the results achieved within several German and European projects. T2 - Fiber optic sensors and applications VII CY - Orlando, FL, USA DA - 2010-04-07 KW - Distributed sensors KW - Brillouin sensors KW - Polymer optical fibers (POF) KW - POF sensors KW - POF OTDR KW - Strain sensors KW - Technical textiles KW - Geotextiles KW - Fiber optic sensors PY - 2010 SN - 9780819481412 DO - https://doi.org/10.1117/12.851013 SN - 0277-786X VL - 7677 IS - 767707 SP - 1 EP - 14 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-21675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - A novel quasi-distributed fibre optic displacement sensor for dynamic measurement N2 - We present a novel technique based on incoherent optical frequency domain reflectometry (OFDR) to measure length changes quasi-distributed between reflection points in optical fibres. The technique enables length changes to be measured with a resolution better than 1 µm and allows for static and dynamic measurement capabilities up to 2 kHz. We demonstrate that dynamic measurements of multiple fibre sections can be conducted independently from each other with high precision. Due to the precise and dynamic measurement capabilities, the proposed sensor system is expected to open new fields of application, especially in the structural-health-monitoring sector. Possible applications are discussed in the paper. KW - Strain sensor KW - Optical frequency domain reflectometry KW - OFDR KW - Optical fibre KW - Fibre sensors KW - Quasi-distributed sensors KW - Dynamic strain measurement PY - 2010 UR - http://iopscience.iop.org/0957-0233/21/7/075205/pdf/0957-0233_21_7_075205.pdf DO - https://doi.org/10.1088/0957-0233/21/7/075205 SN - 0957-0233 SN - 1361-6501 VL - 21 IS - 7 SP - 075205-1 - 075205-6 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-21812 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira, Rui A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Michaud, V. T1 - Development of adaptive composites with embedded plastic optic fibres N2 - This study discusses the development of advanced composite materials with sensing capabilities obtained from the embedment of long period gratings in microstructured plastic optical fibres (mPOF-LPG). The mPOF-LPG was embedded in a carbon fibre reinforced polymer (CFRP) unidirectional laminate manufactured in autoclave. Processing steps were established in order to insure that mPOF does not suffer significant optical and structural degradation. The strain and temperature responses of the embedded mPOF-LPG were investigated. T2 - ICRACM 2010 - 3rd International conference on recent advances in composite materials CY - Limoges, France DA - 2010-12-13 KW - Polymer composites KW - Optical fibre sensors KW - mPOF-LPG KW - SHM PY - 2010 IS - Polymer composite session / FP-Oliveira SP - 1 EP - 6 AN - OPUS4-23040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Peter A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Wendt, Mario A1 - Wosniok, Aleksander A1 - Schneider-Gloetzl, J. A1 - Gloetzl, R. T1 - Distributed fibre optic sensors embedded in technical textiles for monitoring of geotechnical and masonry structures T2 - Monitoring technologies workshop - MoDeRn (Proceedings) CY - Troyes, France DA - 2010-06-07 PY - 2010 IS - OP.7 SP - 71 EP - 72 AN - OPUS4-23041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Witt, Jens A1 - Schukar, Marcus ED - Ecke, Wolfgang ED - Kara J. Peters, ED - Norbert G. Meyendorf, T1 - Smart technical textiles with integrated POF sensors N2 - Fiber optic sensors based on polymer optical fibers (POF) take advantage of the high elasticity and high break-down strain of POF. Because of their outstanding elastic properties, POF are well suited for integration into technical textiles like geotextiles and medical textiles. Smart textiles with incorporated POF sensors, able to sense various mechanical and physical quantities, can be realized. The integration of POF as a sensor into geotextiles for monitoring of displacement of soil is very attractive since POF can be used for distributed strain measurement of strain values of more than 40 %. An online monitoring of critical mechanical deformations of geotechnical structures like dikes, dams, slopes, embankments as well as of masonry structures can be ensured. Medical textiles that incorporate POF sensors can control vital physiological parameters like respiratory movement and can be used for wearable health monitoring of patients requiring a continuous medical assistance and treatment. The biocompatibility of POF is an important criterion for selecting POF as a medical sensor. The paper shows selected examples of using POF sensors for the mentioned monitoring purposes. T2 - Smart Sensor Phenomena, Technology, Networks, and Systems 2008 CY - San Diego, California, USA DA - 2008-03-10 KW - Fiber optic sensors KW - Polymer optical fibers (POF) KW - POF sensors KW - Geotextiles KW - Medical textiles KW - Strain sensor KW - Respiratory monitoring KW - POF OTDR KW - Distributed sensor KW - Geotechnical structures PY - 2008 SN - 978-0-8194-7119-2 DO - https://doi.org/10.1117/12.776758 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 6933 IS - 6933 SP - 69330V-1 - 69330V-15 PB - SPIE CY - Bellingham AN - OPUS4-17680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Krebber, Katerina A1 - Seeger, M. A1 - Thiele, E. A1 - Metschies, H. A1 - Gebreselassie, B. A1 - Münich, J.C. A1 - Stempniewski, L. ED - Francis Berghmans, ED - Mignani, Anna Grazia ED - Cutolo, Antonello ED - Patrick P. Meyrueis, ED - Thomas P. Pearsall, T1 - Distributed strain measurement with polymer optical fibers integrated into multifunctional geotextiles N2 - Fiber optic sensors based on polymer optical fibers (POF) have the advantage of being very elastic and robust at the same time. Unlike silica fibers, standard PMMA POF fibers can be strained to more than 40% while fully maintaining their light guiding properties. We investigated POF as a distributed strain sensor by analysing the backscatter increase at the strained section using the optical time domain reflectometry (OTDR) technique. This sensing ability together with its high robustness and break-down strain makes POF well-suited for integration into technical textiles for structural health monitoring purposes. Within the European research project POLYTECT (Polyfunctional textiles against natural hazards) technical textiles with integrated POF sensors, among others sensors are being developed for online structural health monitoring of geotechnical structures. Mechanical deformation in slopes, dams, dikes, embankments and retrofitted masonry structures is to be detected before critical damage occurs. In this paper we present the POF strain sensor properties, reactions to disturbing influences as temperature and bends as well as the results of the different model tests we conducted within POLYTECT. We further show the potential of perfluorinated graded-index POF for distributed strain sensing with increased spatial resolution and measurement lengths. T2 - Optical Sensors 2008 CY - Strasbourg, France DA - 2008-04-07 KW - Fiber optic sensors KW - OTDR KW - Polymer optical fibers (POF) KW - POF sensors KW - Distributed sensor KW - Strain sensor KW - Geotextiles KW - Structural health monitoring PY - 2008 SN - 978-0-8194-7201-4 DO - https://doi.org/10.1117/12.780508 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 7003 IS - 7003 SP - 700302-1 - 700302-15 PB - SPIE CY - Bellingham AN - OPUS4-17951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Distributed POF Sensors for Structural Health Monitoring - First Practical Applications and Field Tests Results. Invited Paper T2 - 18th International Conference on POF CY - Sydney, Australia DA - 2009-09-09 PY - 2009 AN - OPUS4-20193 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Nöther, Nils A1 - Krebber, Katerina ED - Juergen Brugger, ED - Danick Briand, T1 - Distributed fibre optic sensor system for temperature and strain monitoring based on Brillouin optical-fibre frequency-domain analysis T2 - EUROSENSORS XXIII: sensors, actuators and micro/nanosystems CY - Lausanne, Switzerland DA - 2009-09-06 KW - BOFDA KW - Sideband technique KW - Fibre optic sensors KW - Distributed Brillouin sensors KW - Stimulated Brillouin scattering KW - Nonlinear optics PY - 2009 SN - 1876-6196 SP - 1 EP - 4(?) AN - OPUS4-20235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina ED - Jones, J. ED - Culshaw, B. ED - Ecke, W. ED - López-Higuera, J.M. ED - Willsch, R. T1 - Distributed perfluorinated POF strain sensor using OTDR and OFDR techniques T2 - 20th International conference on optical fibre sensors (Proceedings of SPIE) CY - Edinburgh, Scotland, UK DA - 2009-10-05 KW - Distributed strain sensor KW - Optical fiber sensor KW - Polymer optical fiber KW - POF sensor KW - Structural health monitoring KW - OTDR KW - OFDR PY - 2009 SN - 978-0-8194-7814-6 SN - 0277-786X SP - 75036G-1 - 75036G-4 PB - SPIE, the International Society for Optical Engineering AN - OPUS4-20289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Seeger, M. A1 - Thiele, E. A1 - Metschies, H. A1 - Gebreselassie, B. A1 - Münich, J.C. T1 - Polymer optical fiber sensors for distributed strain measurement and application in structural health monitoring N2 - Polymer optical fiber (POF) sensors have the unique ability to measure high strain distributed along the fiber up to 40% using the optical time-domain reflectometry (OTDR) technique. Both, standard PMMA fibers and perfluorinated (PF) graded-index (GI) POF are introduced and evaluated in potential use and applicability. Further, distributed length change measurement based on cross-correlation analysis of the characteristic fiber signature of PF POF is introduced. We conclude the advances in distributed POF strain sensors technology with respect to application in structural health monitoring. Special focus is on the sensor integration into technical textiles for health monitoring of geotechnical structures and masonry structures. Measurement results of sensor-equipped textiles in different model tests are presented, displacement of soil and cracks in retrofitted masonry structures are detected and evaluated. KW - Distributed strain sensor KW - Optical fiber sensor KW - POF sensors KW - Structural health monitoring PY - 2009 DO - https://doi.org/10.1109/JSEN.2009.2018352 SN - 1530-437X SN - 1558-1748 VL - 9 IS - 11 SP - 1330 EP - 1338 CY - New York, NY, USA AN - OPUS4-20311 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Glötzl, R. A1 - Schneider-Glötzl, J. A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Gabino, L. A1 - Krywult, J. ED - Klapperich, Herbert ED - Jacob, Dieter ED - Azzam, Rafig ED - Wolf, Rainer T1 - Eine neue Geotextilmessmatte mit verteilter Sensortechnik im Einsatz - Suche einer geeigneten Baustelle, Einbauerfahrungen und erste Ergebnisse T2 - 4. Symposium Umweltgeotechnik & 5. Freiberger Geotechnik-Kolloquium & Fachausstellung CY - Freiberg, Deutschland DA - 2009-06-04 PY - 2009 SN - 1613-4753 IS - Publication 7 SP - 1 EP - 9(?) CY - Freiberg AN - OPUS4-20400 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Glötzl, R. A1 - Schneider-Glötzl, J. A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Gabino, L. A1 - Krywult, J. A1 - Krywult, L. T1 - First results of a field test in Belchatow brown coal mine to investigate creeping slopes T2 - VI. International brown coal mining congress "Brown coal - energy - environment - future" CY - Belchatów, Poland DA - 2009-05-18 PY - 2009 SN - 978-83-88316-85-2 SP - 57 EP - 64 PB - Art-Teskt CY - Kraków, Poland AN - OPUS4-20401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasinathan, Murugesan A1 - Rao, C.B. A1 - Murali, N. A1 - Jayakumar, T. A1 - Raj, B. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Analysis of stimulated Brillouin scattering characteristics in frequency domain T2 - ICOP 2009 - International conference on optics & photonics CY - Chandigarh, India DA - 2009-10-30 KW - BOFDA KW - Fibre optic sensors KW - Distributed Brillouin sensors KW - Stimulated Brillouin scattering KW - Nonlinear optics PY - 2009 SP - 1 EP - 5(?) AN - OPUS4-21150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasinathan, Murugesan A1 - Rao, C.B. A1 - Murali, N. A1 - Jayakumar, T. A1 - Raj, B. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Use of Brillouin optical time domain analyser in testing of adhesive bonding T2 - SENNET`09 - International conference on sensors and related networks CY - Vellore, India DA - 2009-12-08 KW - Brillouin KW - Frequency domain analysis KW - Time domain analysis KW - Adhesive KW - Bond evaluation KW - Temperature KW - Strain KW - Distributed sensor PY - 2009 SP - 190 EP - 192 CY - Vellore, India AN - OPUS4-21151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina T1 - Distributed strain measurement in perfluorinated polymer optical fibres using optical frequency domain reflectometry N2 - We present the latest advances in distributed strain measurement in perfluorinated polymer optical fibres (POFs) using backscatter techniques. Compared to previously introduced poly(methyl methacrylate) POFs, the measurement length can be extended to more than 500 m at improved spatial resolution of a few centimetres. It is shown that strain in a perfluorinated POF can be measured up to 100%. In parallel to these investigations, the incoherent optical frequency domain reflectometry (OFDR) technique is introduced to detect strained fibre sections and to measure distributed length change along the fibre with sub-millimetre resolution by applying a cross-correlation algorithm to the backscatter signal. The overall superior performance of the OFDR technique compared to the optical time domain reflectometry in terms of accuracy, dynamic range, spatial resolution and measurement speed is presented. The proposed sensor system is a promising technique for use in structural health monitoring applications where the precise detection of high strain is required. KW - Distributed strain sensor KW - Optical fibre sensor KW - Polymer optical fibre KW - POF sensor KW - Structural health monitoring KW - OTDR KW - OFDR PY - 2010 DO - https://doi.org/10.1088/0957-0233/21/9/094023 SN - 0957-0233 SN - 1361-6501 VL - 21 IS - 9 SP - 094023-1 - 094023-6 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-22379 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina ED - Santos, J.L. ED - Culshaw, B. ED - López-Higuera, J.M. ED - MacPherson, W.N. T1 - A novel fiber optic technique for quasi-distributed and dynamic measurement of length change and refractive index N2 - We present a novel technique for dynamic and simultaneous measurement of displacement and refractive indices at multiple reflection points in optical fibers. This quasi-distributed sensor is based on the incoherent optical frequency domain reflectometry (I-OFDR) technique and allows for m-resolution length change measurement and precise refractive index measurement. We show that the dynamic measurement ability and the simple sensor design allows for new applications in the field of structural health monitoring and chemical process control. T2 - 4th European workshop on optical fibre sensors CY - Porto, Portugal DA - 2010-09-08 KW - Quasi-distributed sensor KW - Strain sensor KW - Length change measurement KW - Optical fiber sensor KW - Refractive index sensor KW - Structural health monitoring KW - OFDR PY - 2010 SN - 978-0-8194-8083-5 DO - https://doi.org/10.1117/12.866325 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7653 SP - 76532V-1 - 76532V-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-22380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira, Rui A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Michaud, V. T1 - Advanced composite materials with embedded POF sensors for structural health monitoring N2 - A long period grating (LPG) mechanically imprinted in a microstructured polymer optical fibre (mPOF) is embedded in a carbon fibre reinforced polymer (CFRP) unidirectional laminate. Processing steps were established in order to ensure that mPOF does not suffer significant degradation. The strain and temperature responses of the embedded mPOF-LPG were then investigated. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - P-25 SP - 1 EP - 4 AN - OPUS4-22381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Quasi-distributed and dynamic length change measurement in polymer optical fibers N2 - We present a novel technique based on the incoherent optical frequency domain reflectometry (l-OFDR) technique for dynamic (2 kHz) and quasi-distributed length change measurement in polymer optical fibers (POF). The extreme strain sensing capabilities (> 125 %) and cyclic load behaviour of perfluorinated POF are investigated using this technique. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - Sensors-2 SP - 1 EP - 4 AN - OPUS4-22382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina T1 - Distributed strain and length change measurement in POF using optical frequency domain reflectometry N2 - We show that the incoherent optical frequency domain (l-OFDR) technique provides superior performance compared to standard OTDR techniques in terms of spatial resolution and measurement time. The distributed strain measurement capabilities of perfluorinated POF up 100 % strain are shown and distributed length change measurement using correlation techniques and OFDR are presented. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - Sensors-2 SP - 1 EP - 4 AN - OPUS4-22383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Schukar, Marcus A1 - Wendt, Mario A1 - Witt, Jens T1 - Distributed POF sensors - recent progress and new challenges N2 - The potential of the use of POF as distributed sensors in several application fields has been successfully demonstrated. The distributed POF sensors have moved from the laboratory to the field. The paper presents the recent progress in the development of distributed POF sensors and addresses the main challenges to this innovative technology. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - Sensors-2 SP - 1 EP - 4 AN - OPUS4-22305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - The impact of temperature and humidity on the backscatter profile of PMMA POF N2 - In this paper the influence of combined temperature and strain changes as well as changes of moisture content on polymer optical fibers made of polymethyl methacrylat (PMMA) is investigated. The increase of the scattering coefficient with increasing temperature for various strain levels is observed and quantified. The measurement results of influence of humidity on scattering intensity of PMMA-POF encourage to porpose these as a distributed humidity sensor. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 KW - POF distributed sensing Rayleigh KW - Humiditiy KW - OTDR KW - Strain PY - 2010 SP - 1 EP - 7(?) AN - OPUS4-22685 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Liehr, Sascha A1 - Krebber, Katerina ED - Santos, J.L. ED - Culshaw, B. ED - López-Higuera, J.M. ED - MacPherson, W.N. T1 - Distributed humidity sensing based on Rayleigh scattering in polymer optical fibers N2 - In this document a new distributed sensor based on Rayleigh scattering in polymer optical fibers (POF) is proposed and first measurement results of the proposed sensor are shown. Different from Silica glas optical fibers POF absorb high quantities of water resulting in a change of their molecular structure and thereby reducing the present small scattering centers in areas of high humidity. The interdependence between scattering intensity and relative humidity is being investigated in case of steady cycles as well as stepwise changes of humidity and in the presence of moisture. A quantitative measure of humidity and scattering is presented. T2 - 4th European workshop on optical fibre sensors CY - Porto, Portugal DA - 2010-09-08 KW - POF KW - Distributed sensing KW - Rayleigh KW - Scattering KW - OTDR KW - Humidity PY - 2010 SN - 978-0-8194-8083-5 DO - https://doi.org/10.1117/12.866279 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7653 SP - 76533X-1 - 76533X-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-22686 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Narbonneau, F. A1 - De Jonckheere, J. A1 - Jeanne, M. A1 - Kinet, D. A1 - Witt, Jens A1 - Krebber, Katerina A1 - Paquet, B. A1 - Depré, A. A1 - D´Angelo, L.T. A1 - Thiel, T. A1 - Logier, R. ED - Popp, J. T1 - OFSETH: Optical technologies embedded in smart medical textile for continuous monitoring of respiratory motions under magnetic resonance imaging N2 - The potential impact of optical fiber sensors embedded into medical textiles for the continuous monitoring of the patient during Magnetic Resonance Imaging (MRI) is now proved. We report how two pure optical technologies can successfully sense textile elongation between, 0% and 3%, while maintaining the stretching properties of the textile substrates for a good comfort of the patient. Investigating influence of different patients' morphology as well as textile integration issues to let free all vitals organs for medical staff actions, the OFSETH harness allows a continuous measurement of respiration movements. For example, anaesthesia for MRI examination uses the same drugs as for any surgical procedure. Even if spontaneous respiration can be preserved most of the time, spontaneous respiration is constantly at risk of being impaired by anaesthetic drugs or by upper airway obstruction. Monitoring of the breathing activity is needed to assess adequate ventilation or to detect specific obstruction patterns. Moreover artefacts due to physiological motions induce a blooming effect on the MRI result. The use of synchronisation devices allows reducing these effects. Positioned at certain strategic places according to the investigated organ, the presented sensors could constitute an efficient and adapted solution for respiratory synchronisation of the MRI acquisition. KW - MRI KW - Smart textile KW - Healthcare monitoring KW - Optical sensor KW - FBG KW - Respiratory sensor PY - 2010 SN - 9780819481887 DO - https://doi.org/10.1117/12.854386 VL - 7715 SP - 77151D-1 - 77151D-12 AN - OPUS4-22839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wosniok, Aleksander A1 - Krywult, L. A1 - Liehr, Sascha A1 - Krebber, Katerina A1 - Wendt, Mario A1 - Chrost, A. T1 - Monitoring konstrukcji ziemnych przy zastosowaniu rozlozonych przestrzennie swiatlowodowych sensorów optycznych, zintegrowanych w geosyntetykach KW - Fibre optic sensor KW - Spatial distributed sensor KW - Polymer optical fibre (POF) KW - Glass optical fibre (GOF) KW - POF OTDR KW - Brillouin sensor KW - BOTDA KW - BOFDA KW - Fibre Bragg grating (FBG) KW - Geosynthetics KW - Geotextiles KW - Technical textiles PY - 2011 UR - http://journals.bg.agh.edu.pl/GORNICTWO/2011-02/GG_2011_2_63.pdf SN - 1732-6702 SN - 0138-0990 VL - 35 IS - 2 SP - 597 EP - 604 PB - Uczelniane Wydawn. Naukowo-Dydaktyczne AGH CY - Kraków AN - OPUS4-23418 LA - pol AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thiele, E. A1 - Erth, H. A1 - Helbig, R. A1 - Werth, K. A1 - Glötzl, R. A1 - Schneider, J. A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Schlurmann, T. A1 - Saathoff, F. T1 - Sensitive Textilstrukturen zur Deichüberwachung T2 - BAUTEX 2008, 8. Sächsisches Bautextilien-Symposium "Bauen mit Geokunststoffen" CY - Chemnitz, Deutschland DA - 2008-01-24 PY - 2008 SP - 1 EP - 5 CY - Chemnitz AN - OPUS4-17448 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Improvements of the distributed strain sensor based on optical time domain reflectometry measurement in polymer optical fibers N2 - Sensing characteristics of standard polymer optical fibers (POF) are further studied using the optical time domain reflectometry (OTDR) technique. The level of the backscattering inside POF, which highly increases at locations where strain is applied to the fiber, is further investigated with respect to spectral behavior, strain rate and span of time from the stretching event. An algorithem to overcome the problem of the decrease of spatial resolution as a result of pulse broadening due to modal disperion, is proposed. The research is carried out on the background of the development of a new strain sensor that is integrated in technical textiles. T2 - 17th International Conference on Plastic Optical Fibers (POF 2008) CY - Santa Clara, California, USA DA - 2008-08-25 KW - Distributed strain sensor KW - Optical fiber sensor KW - POF KW - Scatter KW - PMMA KW - Spatial resolution PY - 2008 IS - Paper 1 SP - 1 EP - 5 AN - OPUS4-18210 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina T1 - Perfluorinated graded-index polymer optical fibers for distributed measurement of strain N2 - Recently, we have proposed, to our knowledge for the first time, to use perfluorinated graded-index polymer optical fiber (POF) for distributed measurement of strain. Thanks to their low attenuation and low modal dispersion compared to standard-POF, this fiber type allows to extend the measurement length to more than 500 meters at increased spatial resolution. In this paper, two mechanisms for strain sensing are introduced. As in standard PMMA POF, strain in the fiber can be detected by evaluating the local backscatter increase occurring at strained fiber sections. Further, we propose, to our knowledge for the first time, a true distributed length change measurement in POF using cross-correlation analysis of the fiber’s characteristic backscatter signature. Using this technique, it is possible to measure relative displacement between different fiber sections avoiding signal fading failures that are inherent in other measurement principles. Cross-sensitivities to the sensor signal, as fiber bends and temperature, are investigated and quantified. T2 - 17th International Conference on Plastic Optical Fibers (POF 2008) CY - Santa Clara, California, USA DA - 2008-08-25 KW - Distributed strain sensor KW - Optical fiber sensor KW - Perfluorinated POF KW - POF sensors PY - 2008 IS - Paper 64 SP - 1 EP - 5 AN - OPUS4-18209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina ED - Francis Berghmans, ED - Mignani, Anna Grazia ED - Cutolo, Antonello ED - Patrick P. Meyrueis, ED - Thomas P. Pearsall, T1 - A distributed fiber optic sensor system for dike monitoring using Brillouin frequency domain analysis T2 - Optical Sensors 2008, April 7-10, 2008 CY - Strasbourg, France DA - 2008-04-07 KW - BOFDA KW - Brillouin sensing KW - Distributed strain measurement KW - Dike monitoring KW - Sensor-based geotextiles KW - Fibre optic sensors KW - Distributed sensors KW - Brillouin scattering PY - 2008 SN - 978-0-8194-7201-4 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7003 SP - 700303-1 - 700303-9 PB - SPIE CY - Bellingham AN - OPUS4-18274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wosniok, Aleksander A1 - Nöther, Nils A1 - Krebber, Katerina A1 - Thiele, E. T1 - Distributed monitoring of mechanical deformation in river dikes T2 - EUROSENSORS XXII CY - Dresden, Germany DA - 2008-09-07 KW - Fiber optic sensor KW - Distributed Brillouin sensor KW - Dike monitoring PY - 2008 SN - 978-3-00-025217-4 SP - 1457 EP - 1460 AN - OPUS4-18322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Thiele, E. ED - Ecke, Wolfgang ED - Kara J. Peters, ED - Norbert G. Meyendorf, T1 - A distributed fiber optic sensor system for dike monitoring using Brillouin optical frequency domain analysis N2 - We report on the development of a complete system for spatially resolved detection of critical soil displacement in river embankments. The system uses Brillouin frequency domain analysis (BOFDA) for distributed measurement of strain in silica optical fibers. Our development consists of the measurement unit, an adequate coating for the optical fibers and a technique to integrate the coated optical fibers into geotextiles as they are commonly used in dike construction. We present several laboratory and field tests that prove the capability of the system to detect areas of soil displacement as small as 2 meters. These are the first tests of truly distributed strain measurements on optical fibers embedded into geosynthetics. T2 - Smart Sensor Phenomena, Technology, Networks, and Systems 2008 CY - San Diego, California, USA DA - 2008-03-10 KW - BOFDA KW - Brillouin sensing KW - Distributed strain measurement KW - Dike monitoring KW - Sensor-based geotextiles KW - Fiber optic sensors KW - Distributed sensors KW - Brillouin scattering PY - 2008 SN - 978-0-8194-7119-2 DO - https://doi.org/10.1117/12.775133 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 6933 SP - 69330T-1 - 69330T-9 PB - SPIE CY - Bellingham AN - OPUS4-18250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Thiele, E. ED - W. Ostachowicz, ED - J. Holnicki-Szulc, ED - C. Mota Soares, T1 - Dike monitoring using fiber sensor-based geosynthetics N2 - We report on the development of distributed fiber sensors and their integration into geosynthetics as they are commonly used in the construction of dikes and dams for flood protection. The sensing system uses Stimulated Brillouin Scattering (SBS) in silica optical fibers. Using the Brillouin frequency analysis, the system is capable of detecting changes in both strain and temperature along the optical fibers. The strain experienced by the optical fibers corresponds to the deformation of the geosynthetics in case of a critical soil displacement. To satisfy requirements of dike structures, the system will be optimized to detect soil displacement with a spatial resolution of 5 m or less over a length in the range of 10 km. These rather modest requirements leave space for optimization on resolution of the measurement values, measurement time and cost efficiency. To our knowledge, this is the first distributed fiber sensor using SBS that is especially designed for the monitoring of soil displacement in dikes which is made possible by a novel method for the integration of optical fibers into different types of geosynthetics. T2 - 3. ECCOMAS Thematic Conference on Smart Structures and Materials CY - Gdansk, Poland DA - 2007-07-09 KW - Fiber optic sensors KW - Dike monitoring KW - SBS KW - Distributed strain sensors KW - Distributed brillouin sensors KW - Geosynthetics PY - 2007 SN - 978-83-88237-03-4 IS - Paper 03 SP - 1 EP - 13 PB - Institute of Fluid-Flow Machinery CY - Gda´nsk AN - OPUS4-18253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Krebber, Katerina T1 - Optical Fibre Sensor Application in Civil and Geotechnical Engineering T2 - 1. Asian-Pacific Conference on Optical Fibre Sensors and 3rd International Symposium on Advances & Trends in Fiber Optics CY - Chengdu, China DA - 2008-11-07 PY - 2008 AN - OPUS4-18336 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Krebber, Katerina ED - Jones, J. ED - Culshaw, B. ED - Ecke, W. ED - López-Higuera, J.M. ED - Willsch, R. T1 - A new model to calculate the Rayleigh scattering profiles in polymer optical fibers for distributed strain sensing N2 - This paper presents new methods to calculate and interpret Rayleigh scattering profiles in polymer optical fibers (POF) recorded by optical time domain reflectometry (OTDR). In contrast to Silica glass optical fibers (GOF), POF experience inhomogeneous stress when being strained, resulting in small scattering centers which allow for a new distributed sensor based on POF. New methods to overcome issues like blurring due to modal dispersion, uncertainties due to inhomogenious losses in the fiber and signal degradation due to viscoelastic creep in the polymer, are presented, for the first time to our knowledge. T2 - 20th International conference on optical fibre sensors (Proceedings of SPIE) CY - Edinburgh, Scotland, UK DA - 2009-10-05 KW - POF KW - Distributed sensing KW - Rayleigh KW - Scattering KW - OTDR KW - Distributed strain sensor KW - Optical fiber sensor KW - PMMA KW - Spatial resolution PY - 2009 SN - 978-0-8194-7814-6 DO - https://doi.org/10.1117/12.835361 SN - 0277-786X SP - 75036I-1 - 75036I-4 PB - SPIE, the International Society for Optical Engineering AN - OPUS4-20496 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nöther, Nils A1 - Lenke, Philipp A1 - Krebber, Katerina ED - Jones, J. ED - Culshaw, B. ED - Ecke, W. ED - López-Higuera, J.M. ED - Willsch, R. T1 - A novel signal restoration method in the frequency domain to enhance spatial resolution in distributed Brillouin sensing T2 - 20th International conference on optical fibre sensors (Proceedings of SPIE) CY - Edinburgh, Scotland, UK DA - 2009-10-05 KW - Fiber-optic sensing KW - Distributed Brillouin sensing KW - Spatial resolution KW - Deconvolution PY - 2009 SN - 978-0-8194-7814-6 SN - 0277-786X SP - 75032F-1 - 75032F-4 PB - SPIE, the International Society for Optical Engineering AN - OPUS4-20467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Thiele, E. ED - Bernadette Havranek, ED - Masoud Motavalli, ED - Urs Meier, T1 - A distributed fiber-optic sensing system for monitoring of large geotechnical structures T2 - 4th International conference on structural health monitoring of intelligent infrastructure CY - Zurich, Switzerland DA - 2009-07-22 KW - Structural health monitoring KW - Distributed sensing KW - Geotextiles KW - Dike monitoring PY - 2009 SN - 978-3-905594-52-2 SP - 1 EP - 9 CY - Zurich, Switzerland AN - OPUS4-20468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider-Gloetzl, J. A1 - Gloetzl, R. A1 - Krebber, Katerina A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Wosniok, Aleksander T1 - Geotechnical monitoring of construction activities by distributed fiber optic sensors embedded in geotextiles T2 - 5th European workshop on structural-health-monitoring 2010 CY - Sorrento, Italy DA - 2010-06-29 KW - Foundation engineering KW - Geotechnical monitoring KW - Smart textiles KW - Distributed fiber optic sensors KW - POF sensors KW - Brillouin sensors PY - 2010 IS - SS4-07 SP - 1 EP - 6 AN - OPUS4-21872 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Wendt, Mario A1 - Wosniok, Aleksander ED - Santos, J.L. ED - Culshaw, B. ED - López-Higuera, J.M. ED - MacPherson, W.N. T1 - Distributed fiber optic sensors embedded in technical textiles for structural health monitoring N2 - Technical textiles with embedded distributed fiber optic sensors have been developed for the purposes of structural health monitoring in geotechnical and civil engineering. The distributed fiber optic sensors are based on Brillouin scattering in silica optical fibers and OTDR in polymer optical fibers. Such "smart" technical textiles can be used for reinforcement of geotechnical and masonry structures and the embedded fiber optic sensors can provide information about the condition of the structures and detect the presence of any damages and destructions in real time. Thus, structural health monitoring of critical geotechnical and civil infrastructures can be realized. The paper highlights the results achieved in this innovative field in the framework of several German and European projects. T2 - 4th European workshop on optical fibre sensors CY - Porto, Portugal DA - 2010-09-08 KW - Fiber optic sensor KW - Distributed sensor KW - Brillouin sensor KW - Polymer optical fibers (POF) KW - POF sensor KW - POF OTDR KW - Strain sensor KW - Technical textiles KW - Geotextiles PY - 2010 SN - 978-0-8194-8083-5 DO - https://doi.org/10.1117/12.868052 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7653 SP - 76530A-1 - 76530A-12 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-21948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Distributed fibre optic sensors embedded in technical textiles for monitoring of geotechnical and masonry structures T2 - European Workshop on Monitoring Technologies (MoDeRn) - Potential Application to Monitoring of Geological Repositories for Radioactive Waste CY - Troyes, France DA - 2010-06-07 PY - 2010 AN - OPUS4-22023 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Distributed fiber optic sensors embedded in technical textiles for structural health monitoring T2 - 4th European Workshop on Optical Fibre Sensors (EWOFS) CY - Oporto, Portugal DA - 2010-09-08 PY - 2010 AN - OPUS4-22059 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Protection of critical infrastructure using fiber optic sensors in technical textiles T2 - SPIE International Conference "Defense, Security + Sensing" CY - Orlando, FL, USA DA - 2010-04-05 PY - 2010 AN - OPUS4-22083 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schallert, Matthias A1 - Krebber, Katerina A1 - Hofmann, Detlef A1 - Habel, Wolfgang A1 - Stahlmann, J. T1 - Auswahl geeigneter Fasersensorprinzipien für Anwendungen in der Geotechnik T2 - Fachseminar "Messen in der Geotechnik 2004" CY - Braunschweig, Deutschland DA - 2004-09-09 PY - 2004 SN - 3-927610-68-2 N1 - Serientitel: Mitteilung des Instituts für Grundbau und Bodenmechanik - Technische Universität Braunschweig – Series title: Mitteilung des Instituts für Grundbau und Bodenmechanik - Technische Universität Braunschweig IS - 77 SP - 309 EP - 328 PB - Inst. für Grundbau und Bodenmechanik, Techn. Univ. CY - Braunschweig AN - OPUS4-4424 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Integration von Fasersensoren zur Schadensfrüherkennung und -vermeidung T2 - Fachtagung "Windkraftanlagen Sicherheit und Zuverlässigkeit" CY - Darmstadt, Germany DA - 2004-11-04 PY - 2004 AN - OPUS4-4638 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Krebber, Katerina A1 - Gutmann, Toivo A1 - Schram, C. A1 - Meyer, D. T1 - Fibre Bragg Grating Sensors to Monitor the Rotor Blades of Wind Turbines - Criteria and Method to put them to the Best Possible Use T2 - 7th German Wind Energy Conference (DEWEK 2004) "Where Industry meets Science" CY - Wilhelmshaven, Germany DA - 2004-10-20 KW - Windkraftanlagen PY - 2004 PB - Deutsches Windenergie-Institut CY - Wilhelmshaven AN - OPUS4-5784 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Habel, Wolfgang A1 - Gutmann, Toivo A1 - Schramm, Ch. T1 - Monitoring of the rotor blades of wind turbines by fibre optic sensors N2 - In order to monitor the mechanical behaviour of the rotor blades of wind turbines, fibre optic sensors are increasingly attached to or embedded in the blades. Usually, fibre Bragg grating sensors arrays are then used. In order to investigate how stable and reliably work such sensors, fibre Bragg grating arrays were embedded into textile-reinforced composite. Long-term temperature and tensile (fatigue) tests have been carried out with composite structure specimens. This paper reports on selected results of the tests and discusses important reliability aspects with regard to the fibre design and the fibre material. T2 - 3rd International Conference on Materials Testing "TEST 2005" CY - Nuremberg, Germany DA - 2005-05-10 KW - Faseroptische Sensorik PY - 2005 SP - B.5-55-B.5-60 PB - AMA Service GmbH CY - Nürnberg AN - OPUS4-7440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krebber, Katerina A1 - Habel, Wolfgang A1 - Gutmann, Toivo A1 - Schram, C. T1 - Fiber Bragg grating sensors for monitoring of wind turbine blades N2 - Fiber Bragg grating sensor arrays can be used to monitor the mechanical behavior of rotor blades of wind turbines. In order to investigate how stable and reliably work such sensors, different fiber Bragg gratings were embedded into textile-reinforced composite. Long-term temperature and tensile (fatigue) tests have been carried out with composite structure specimens. This paper reports on selected results of the tests and discusses important reliability aspects with regard to the fiber design and the fiber material. T2 - 17th International Conference on Optical Fibre Sensors CY - Bruges, Belgium DA - 2005-05-23 KW - Fiber Bragg grating sensors KW - Rotor blades KW - Wind turbines KW - Strain monitoring PY - 2005 SN - 0-8194-5855-4 VL - 5855 IS - Part 2/2 SP - 1036 EP - 1039 PB - SPIE CY - Bellingham AN - OPUS4-7490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krebber, Katerina A1 - Henschel, H. A1 - Weinand, U. T1 - Fibre Bragg gratings as high dose radiation sensors? N2 - We have measured for the first time the shift of the Bragg wavelength and other parameters of fibre Bragg gratings (FBGs) exposed to radiation at different wavelengths up to a dose of 100 kGy. The results show that the FBG sensitivity to radiation increases from 820 nm to 1516 nm so that FBGs with higher Bragg wavelength, e.g. 1.55 µm, are good candidates for high dose radiation sensing: no saturation was observed up to 100 kGy and the measured wavelength shift was fairly independent on the radiation dose rate. T2 - 17th International Conference on Optical Fibre Sensors CY - Bruges, Belgium DA - 2005-05-23 KW - Fibre Bragg gratings KW - Radiation effects KW - Gamma radiation KW - Fibre sensors KW - Radiation sensors KW - Radiation dosimetry PY - 2006 DO - https://doi.org/10.1088/0957-0233/17/5/S26 SN - 0957-0233 SN - 1361-6501 VL - 17 SP - 1095 EP - 1102 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-7491 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schram, Ch. A1 - Krebber, Katerina A1 - Habel, Wolfgang T1 - Glasfasersensoren für Rotorblätter KW - Glasfasern KW - Faser-Bragg-Gitter KW - Windenergieanlagen KW - Rotorblätter PY - 2005 SN - 1436-8773 SN - 0946-7556 VL - 15 IS - 7 SP - 32 EP - 34 PB - SunMedia CY - Hannover AN - OPUS4-11213 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - "Sensitive" Werkstoffe mittels faseroptischer Sensoren. T2 - BAM-Kolloquium CY - Berlin, Germany DA - 2005-11-09 PY - 2005 AN - OPUS4-11628 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Monitoring of the rotor blades ofwind turbines by fibre optic snesors. T2 - TEST 2005, 3rd. International Conference on Material Testing CY - Nuremberg, Germany DA - 2005-05-10 PY - 2005 AN - OPUS4-11630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Fibre Bragg gratings as high dose radiation sensors? T2 - OFS 2005 17th International Conference on Optical Fibre Sensors CY - Bruges, Belgium DA - 2005-05-23 PY - 2005 AN - OPUS4-11631 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Integration Faser-Bragg-Gitter-Sensoren in Hochleistungsverbundwerkstoffe zur Früherkennung von Schädigungen. T2 - Vortrag auf der Sitzung des GESA-AK 17 "Faseroptische Sensorik" CY - Cologne, Germany DA - 2005-01-20 PY - 2005 AN - OPUS4-11732 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Protection of critical infrastructure usingfibre optic sensors T2 - Europäische Konferenz "Safety and Security Systems in Europe" CY - Potsdam, Germany DA - 2006-11-30 PY - 2006 AN - OPUS4-13991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thiele, E. A1 - Erth, H. A1 - Arnold, R. A1 - Habel, Wolfgang A1 - Krebber, Katerina A1 - Döring, H. A1 - Glötzl, R. T1 - Applikation optischer Fasern in Textilflächen T2 - 45. Internationale Chemiefasertagung CY - Dornbirn, Österreich DA - 2006-09-21 KW - Optische Fasern KW - Faseroptische Sensoren KW - Geotextilien PY - 2006 SP - 1 EP - 5(?) CY - Dornbirn AN - OPUS4-14457 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Dantan, Nathalie A1 - Hofmann, Detlef A1 - Krebber, Katerina A1 - Schallert, Matthias T1 - Ausgewählte Anwendungsbeispiele faseroptischer Sensoren im Ingenieurbau und in der Geotechnik T2 - Ingenieurvermessung 07 CY - Graz, Österreich DA - 2007-04-17 PY - 2007 SP - 281 EP - 294 PB - Wichmann CY - Graz AN - OPUS4-14760 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grillet, A. A1 - Kinet, D. A1 - Witt, Jens A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Pirotte, F. A1 - Depré, A. T1 - Optical fibre sensors embedded into medical textiles for monitoring of respiratory movements in MRI environment T2 - EWOFS 2007 - 3rd European Workshop on Optical Fibre Sensors CY - Napoli, Italy DA - 2007-07-04 KW - Respiration sensor KW - Fibre optic sensor KW - POF KW - POF sensor KW - Bending sensor KW - Strain sensor KW - OTDR KW - Medical textiles PY - 2007 SN - 9780819467614 SN - 0277-766X VL - 6619 SP - 66191R-1 - 66191R-4 AN - OPUS4-15842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krebber, Katerina T1 - Protection of Critical Infrastructure Using Fibre Optic Sensors PY - 2007 SN - 0948-3128 IS - 4 SP - 12 EP - 14 CY - Teltow AN - OPUS4-15694 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Poisel, H. A1 - Kalymnios, D. A1 - Krebber, Katerina A1 - Scully, P. A1 - Werneck, M. A1 - Zubia, J. T1 - POF Sensors - applications in every day's life T2 - 33rd European Conference and Exhibition on Optical Communication CY - Berlin, Germany DA - 2007-09-16 PY - 2007 VL - 2 SP - 103 EP - 106 PB - VDI-Verl. CY - Berlin AN - OPUS4-15943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witt, Jens A1 - Bunge, C.-A. A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Real-time strain sensing based on POF OTDR N2 - We investigate two real-time strain sensing principles based on the optical time-domain reflectometry (OTDR) in polymer optical fibres (POF). The first sensing principle uses the increase of the level of backscattered light in a stretched POF. The second sensing principle uses the effect of losses due to bending. T2 - 16th International Conference on Plastic Optical Fibers (POF 2007) CY - Turin, Italy DA - 2007-09-10 KW - Strain sensor KW - Fibre optic sensor KW - POF sensor KW - OTDR KW - Strain rate PY - 2007 SP - 210 EP - 213 PB - International Cooperative of Plastic Optical Fibers (ICPOF) CY - Turin, Italy AN - OPUS4-15922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Scheer, M. ED - Bernd Henning, T1 - Strahlungsüberwachung mit Faser-Bragg-Gitter-Sensoren am Elektronenspeicherring BESSY II T2 - 21. Messtechnisches Symposium des Arbeitskreises der Hochschullehrer für Messtechnik e.V, CY - Paderborn, Deutschland DA - 2007-09-20 KW - Faser-Bragg-Gitter KW - Fasersensoren KW - Strahlungssensoren KW - Strahlungseffekte KW - Strahlungsdosimetrie KW - Elektronenspeicherring PY - 2007 SN - 978-3-8322-6539-7 SP - 178 EP - 189 PB - Shaker CY - Aachen AN - OPUS4-16314 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Krebber, Katerina A1 - Dantan, Nathalie A1 - Schallert, Matthias A1 - Hofmann, Detlef ED - Bin Shi, T1 - Recent examples of applied fibre optic sensors in geotechnical areas to evaluate and monitor structural integrity T2 - OSMG-2007 - 2nd International Workshop on Opto-electronic Sensor-based Monitoring in Geo-engineering CY - Nanjing, China DA - 2007-10-18 KW - Fibre optic sensors KW - Monitoring KW - Geotechnique KW - Pile load test KW - pH sensor KW - Geotextile monitoring KW - Ground anchor monitoring KW - Distributed sensor PY - 2007 SP - 27 EP - 35 CY - Nanjing, China AN - OPUS4-16431 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Krebber, Katerina A1 - Weigand, F. A1 - Thiele, E. T1 - Distributed strain measurement with polymer optical fiber integrated in technical textiles using the optical time domain reflectometry technique N2 - The presented research is carried out on the background of the development of a new strain sensor, integrated in technical textiles using the optical time domain reflectometry (OTDR) technique. We investigated the effect of increased scattering in POF due to applied strain as a distributed sensor including research on long-term stability and reliability of this sensor. T2 - 16th International Conference on Plastic Optical Fibers (POF 2007) CY - Turin, Italy DA - 2007-09-10 PY - 2007 SP - 21 EP - 24 PB - International Cooperative of Plastic Optical Fibers (ICPOF) CY - Turin, Italy AN - OPUS4-16435 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lenke, Philipp A1 - Krebber, Katerina A1 - Muthig, M. A1 - Weigand, F. A1 - Thiele, E. ED - W. Ostachowicz, ED - J. Holnicki-Szulc, ED - C. Mota Soares, T1 - Distributed strain measurement using polymer optical fiber integrated in technical textile to detect displacement of soil N2 - Sensing characteristics of polymer optical fibers (POF) are studied using the optical time-domain reflectometry technique. For the first time to our knowledge, investigations are carried out with respect to integration of POF in technical textiles for distributed measurement of mechanical deformation. The research on this new sensor type focuses on its application in monitoring of geotechnical structures such as railway embankments, dikes, slopes and dams. We report on a distributed sensor system using POF integrated in technical textiles as sensing elements for measurement of displacement of soil. This sensor system is very robust – it withstands the integration under rough condition at a construction site – and can detect strain of more than 40 % over distances of more than 100 meters. T2 - 3. ECCOMAS Thematic Conference on Smart Structures and Materials CY - Gdansk, Poland DA - 2007-07-09 KW - OTDR KW - Strain sensor KW - Distributed sensing KW - Fiber optic sensor KW - POF sensor KW - Technical textile KW - Geotextile PY - 2007 SN - 978-83-88237-03-4 IS - Paper 03 SP - 1 EP - 8 PB - Institute of Fluid-Flow Machinery CY - Gda´nsk AN - OPUS4-16437 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Witt, Jens A1 - Schukar, Marcus A1 - Krebber, Katerina ED - Gerald Gerlach, ED - Peter Hauptmann, T1 - Polymeroptische Fasersensoren in der Medizintechnik T2 - 8. Dresdner Sensor-Symposium CY - Dresden, Deutschland DA - 2007-12-10 KW - OTDR KW - POF KW - Faseroptischer Sensor KW - Atmungssensor PY - 2007 SN - 978-3-940046-45-1 N1 - Serientitel: Dresdner Beiträge zur Sensorik – Series title: Dresdner Beiträge zur Sensorik VL - 29 IS - 29 SP - 223 EP - 226 PB - TUDpress, Verlag der Wissenschaften GmbH CY - Dresden AN - OPUS4-16427 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Glötzl, R. A1 - Schneider Glötzl, J. A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Krywult, L. ED - Wintera, J. ED - Kosik, A. ED - Wity, A. T1 - Optical distributed sensing systems and possible applications in geotechnical measuring N2 - In comparison with traditional measuring Systems (pressure cells, piezometers and inclinometers which produce only point measurements) fibre optic sensors are well suited for spatiallydistributed monitoring purposes. The very tiny optical fibres of a diameter of less then 1 mm can operate as sensors in strong electromagnetic fields, under “harsh” explosive and Chemical environments and under ionizing radiation. T2 - XIV Dam monitoring international conference 'safetyof dams - new challenges' ('Bezpieczenstwo zapór - nowe wyzwania') CY - Walbrzych, Poland DA - 13.06.2011 KW - Fibre optic sensor KW - Spatial distributed sensor KW - Polymer optical fibre (POF) KW - Glass optical fibre (GOF) KW - POF OTDR KW - Brillouin sensor KW - BOTDA KW - BOFDA KW - Fibre Bragg grating (FBG) KW - Geosynthetics KW - Geotxtiles KW - Technical textiles PY - 2011 SN - 978-83-61102-53-3 N1 - Serientitel: Monografie - Instytutu Meteorologii i Gospodarki Wodnej – Series title: Monografie - Instytutu Meteorologii i Gospodarki Wodnej IS - Chapter 6 SP - 173 EP - 180 AN - OPUS4-24066 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - A dynamic fiber optic strain and power change sensor N2 - A dynamic and quasi-distributed sensor principle for simultaneous measurement of length changes and optical power changes between reflection points in an optical fiber is presented. The technique is based on the incoherent optical frequency domain reflectometry (I-OFDR). Length change resolutions < 1 µm and measurement repetition rates up to 2 kHz can be achieved using standard single-mode and multi-mode optical fibers. Simultaneous length change and refractive index measurement as well as field test results showing the deformation of a masonry building under seismic load are presented. Promising fields of application for this technique are the structural health monitoring sector and chemical process control. T2 - 21st International conference on optical fibre sensors CY - Ottawa, Canada DA - 15.05.2011 KW - Distributed sensor KW - Strain sensor KW - Optical fiber sensor KW - Structural health monitoring KW - OFDR KW - Dynamic sensor PY - 2011 SN - 978-0-8194-8246-4 DO - https://doi.org/10.1117/12.884577 VL - 7753 SP - 775351-1 EP - 775351-4 AN - OPUS4-24266 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Habel, Wolfgang A1 - Krebber, Katerina T1 - Fiber-optic sensor applications in civil and geotechnical engineering N2 - Different types of fiber-optic sensors based on glass or polymeric fibers are used to evaluate material behavior or to monitor the integrity and long-term stability of load-bearing structure components. Fiber-optic sensors have been established as a new and innovative measurement technology in very different fields, such as material science, civil engineering, light-weight structures, geotechnical areas as well as chemical and high-voltage substations. Very often, mechanical quantities such as deformation, strain or vibration are requested. However, measurement of chemical quantities in materials and structure components, such as pH value in steel reinforced concrete members also provides information about the integrity of concrete structures. A special fiber-optic chemical sensor for monitoring the alkaline state (pH value) of the cementitious matrix in steel-reinforced concrete structures with the purpose of early detection of corrosion-initiating factors is described. The paper presents the use of several fiber-optic sensor technologies in engineering. One example concerns the use of highly resolving concrete-embeddable fiber Fabry-Perot acoustic emission (AE) sensors for the assessment of the bearing behaviour of large concrete piles in existing foundations or during and after its installation. Another example concerns fiber Bragg grating (FBG) sensors attached to anchor steels (micro piles) to measure the strain distribution in loaded soil anchors. Polymer optical fibers (POF) can be — because of their high elasticity and high ultimate strain – well integrated into textiles to monitor their Deformation behaviour. Such 'intelligent' textiles are capable of monitoring displacement of soil or slopes, critical mechanical deformation in geotechnical structures (dikes, dams, and embankments) as well as in masonry structures during and after earthquakes. KW - Fiber-optic sensor KW - Monitoring KW - Earthquake damage assessment KW - Steel-reinforced structures KW - pH sensor KW - Geotextiles KW - Distributed sensor PY - 2011 DO - https://doi.org/10.1007/s13320-011-0011-x SN - 1674-9251 VL - 1 IS - 3 SP - 268 EP - 280 PB - Springer CY - Heidelberg ; Secaucus, NJ AN - OPUS4-24256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nöther, N. A1 - Krebber, Katerina A1 - Schneider-Glötzl, J. T1 - An all-digital implementation of the Brillouin optical frequency domain analysis for long-range distributed strain and temperature monitoring N2 - For long-range measurements in geotechnical and industrial applications, distributed optical fiber sensors have become a tool of increasing importance throughout the past decade. Classic deformation monitoring (performed by strain gauges etc.) and temperature monitoring (Pt100 and alike) deliver data from fixed, single spots of a structure; quasidistributed measurements (fiber bragg gratings) provide a Chain of discrete measurement points along a limited sensing length. In contrast, an opticai fiber connected to a device for distributed strain and temperature sensing (DTSS) will provide a continuous profile of strain and temperature - spatially resolved down to less than 1 m - over a ränge of several tens of kilometers. In DTSS measurements, the nonlinear opticai effect of stimulated Brillouin Scattering (SBS) is employed: two light waves with a stable, tunable frequency offset are injected into opposite ends of the sensing fiber, where they will form a beat pattem, at which parts of the light will be scattered. By matching the frequency offset of the light waves to the propagation of acoustic fluctuation in the opticai fiber, a power transfer from one light wave to the other can be measured; since the acoustic propagation directly shifts with train and temperature of the fiber, these two quantities can be measured by tuning the light waves’ frequency offset. T2 - 8th International symposium on field measurements in geomechanics - FMGM 2011 CY - Berlin, Germany DA - 12.09.2011 PY - 2011 SP - 1 EP - 6 AN - OPUS4-24664 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witt, Jens A1 - Krebber, Katerina A1 - Demuth, J. A1 - Sasek, L. T1 - Fiber optic heart rate sensor for integration into personal protective equipment N2 - This paper reports on a fiber optic sensor for heart rate measurements. The sensor will be integrated into personal protective equipment within the framework of the FP7 EU project i-Protect. Two different sensor prototypes were developed. One is based on fiber Bragg gratings in silica fiber and the other one is based on macrobending effects in polymer optical fiber. T2 - International workshop BioPhotonics 2011 CY - Parma, Italy DA - 08.06.2011 KW - Smart textile KW - Healthcare monitoring KW - Fiber optical sensor KW - FBG KW - Heart rate sensor KW - Macrobending sensor PY - 2011 SN - 978-1-4244-9837-6 DO - https://doi.org/10.1109/IWBP.2011.5954836 IS - Th6.26 SP - 1 EP - 3 AN - OPUS4-24498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witt, Jens A1 - Breithaupt, Mathias A1 - Erdmann, Jessica A1 - Krebber, Katerina T1 - Humidity sensing based on microstructured POF long period gratings N2 - We investigated the capabilities of long period gratings (LPG) in single-mode microstructured polymer optical fibre (mPOF) for humidity sensing. For that mPOF LPGs were exposed to different humidity levels at a constant temperature of 30°C in a climate chamber. During the long term tests, which took up several weeks, the humidity was changed in several steps while mPOF LPG wavelength and fibre attenuation were measured. We also measured the water uptake of mPOF in environment with different relative humidity. T2 - POF 2011 - 20th International conference on plastic optical fibers CY - Bilbao, Spain DA - 14.09.2011 KW - Microstructured polymer optical fibre (mPOF) KW - Long period grating (LPG) KW - Humidity sensor PY - 2011 SP - 1 EP - 6 AN - OPUS4-24501 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina ED - De Roeck, G. ED - Degrande, G. ED - Lombaert, G. ED - Müller, G. T1 - A novel quasi-distributed long-gauge fiber optic strain sensor system for dynamic measurement N2 - We present a novel technique based on incoherent optical frequency domain reflectometry (OFDR) to measure length changes quasi-distributed between reflection points in optical fibres. The technique enables length changes to be measured with a resolution better than 1 µm and allows for static and dynamic measurement capabilities up to 2 kHz. We demonstrate that dynamic measurements of multiple fibre sections can be conducted independently from each other with high precision. Due to the precise and dynamic measurement capabilities, the proposed sensor system is expected to open new fields of application, especially in the structural-health-monitoring sector. Possible applications are discussed in the paper. T2 - EURODYN 2011 - 8th International conference on structural dynamics CY - Leuven, Belgium DA - 04.07.2011 KW - Distributed sensor KW - Strain sensor KW - Optical fiber sensor KW - Structural health monitoring KW - OFDR KW - Length change measurement KW - Dynamic sensor PY - 2011 SN - 978-90-760-1931-4 SP - 2097 EP - 2102 AN - OPUS4-24347 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Simultaneous measurement of temperature and strain distribution using Brillouin scattering in dispersion-shifted fibers N2 - We studied Brillouin gain spectrum characteristics in dispersion-shifted fibers having compound GeO2-doping compositions in the fiber core to realize simultaneous measurement of distributed strain and temperature. Due to various dopant concentration alongside the radius of tested nonzero dispersion-shifted fibers several multiple Brillouin scattering resonances were observed in the stimulated Brillouin spectra arose through backscattering on higher acoustic modes which propagated along the fiber axis. As a result of the varying acoustic velocities, the Brillouin resonance peaks featured different temperature coefficients which can be used to accomplish the simultaneous measurement of fiber strain and temperature. We presented our first measurement results for NZDS Fujikura and LEAF Corning fiber and discussed the superior sensory suitability of the former fiber types. T2 - IEEE Sensors 2011 conference CY - Limerick, Ireland DA - 28.10.2011 KW - Fiber optic sensor KW - Spatial distributed sensor KW - Brillouin gain spectrum (BGS) KW - Nonzero dispersion-shifted fiber (NZDSF) KW - Brillouin sensor KW - BOTDA KW - BOFDA PY - 2011 SN - 978-1-4244-9288-6 SP - 1476 EP - 1479 AN - OPUS4-24828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krebber, Katerina A1 - Habel, Wolfgang T1 - Fibre-optic sensors embedded in geotechnical textiles and concrete piles for structural health monitoring N2 - Fibre-optic sensors are more and more used in geotechnical and civil engineering. There are a big number of applications with the purpose of improvement or proof of the structural integrity. This paper, presents two examples where different fibre sensor types.are exploited for safety-relevant task in geotechnique. Technical textiles with embedded distributed fibre-optic sensors based on Brillouin Scattering in silica optical fibres and OTDR (optical time-domain reflectometry) in polymer optical fibres are presented. Such “smart” technical textiles can be used for reinforcement of geotechnical structures and masonry walls, and the embedded fibre-optic sensors can provide information about the condition of the structures as well as detect the presence of any damage and destructions in real time. Highly sensitive fibre-optic geophones based on Fabry-Perot sensors embedded in large concrete pile can be used for precise measurement of Deformation and wave distribution during static and dynamic pile test. Such sensors make the evaluation of the pile’s integrity and load-bearing capacity easier. KW - Faseroptischer Sensor KW - Verteilter Sensor KW - Brillouin-Sensor KW - Polymeroptischer Sensor KW - POF OTDR KW - Technisches Textil KW - Geotextil KW - Dehnungssensor KW - Geophon KW - Pfahltest KW - Akustische Welle KW - Fabry-Perot KW - Fibre-optic sensor KW - Distributed sensor KW - Polymer optical fibres (POF) KW - POF sensor KW - Strain sensor KW - Technical textiles KW - Geotextiles KW - Geophone KW - Fabry-Perot sensor KW - Pile test KW - Impact KW - Acoustic wave PY - 2011 SN - 0002-5968 VL - 7 SP - 252 EP - 263 PB - Wichmann CY - Heidelberg AN - OPUS4-24816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Glötzl, R. ED - Bock, W.J. ED - Albert, J. ED - Bao, X. T1 - Highly sensitive fiber optic inclinometer - easy to transport and easy to install N2 - We present the status of our work on a tube shaped 3D deformation sensor based on continuously distributed fiber optic sensing. A sensor tube of very large diameter is used to ensure high sensitivity while the transportability and applicability are still comfortable due to our application strategy. The setup is designed to use different measurement techniques in the applied optical fibers including Brillouin based measurements and interferometric optical frequency domain measurements using an OBR 4400 from Luna Technologies. T2 - 21st International conference on optical fiber sensors (OFS 21) CY - Ottawa, Canada DA - 15.05.2011 KW - Inclinometer KW - Bend KW - Sensor KW - Fiber KW - Optic KW - Brillouin KW - OBR PY - 2011 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 7753 SP - 775352-1 EP - 775352-4 AN - OPUS4-24970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Structural health monitoring by smart technical textiles based on fiber optic sensors T2 - International Conference on Structural Health Monitoring of Intelligent Infrastructure, SHMII-5 CY - Cancún, Mexico DA - 2011-12-11 PY - 2011 AN - OPUS4-24960 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina ED - Ramos, G. A. T1 - Structural health monitoring by smart technical textiles based on fiber optic sensors N2 - Technical textiles with embedded distributed fiber optic sensors have been developed for the purposes of structural health monitoring in geotechnical and civil engineering. The distributed fiber optic sensors are based on Brillouin Scattering in silica optical fibers and OTDR in polymer optical fibers. Such “smart” technical textiles can be used for reinforcement of geotechnical and masonry structures and the embedded fiber optic sensors can provide information about the condition of the structures and detect the presence of any damages and destructions in real time. Thus, structural health monitoring of critical geotechnical and civil infrastructures can be realized. The paper highlights the results achieved in this innovative field in the framework of several German and European projects. T2 - SHMII-5 - 5th International conference on structural health monitoring of intelligent infrastructure CY - Cancún, Mexico DA - 11.12.2011 PY - 2011 IS - Keynote Lecture SP - 1 EP - 10 PB - National Autonomous University of Mexico CY - Mexico City AN - OPUS4-25261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Polymer Optical Fibres in Sensing - Applications & Future Demands T2 - IEEE Sensors 2011 Conference CY - Limerick, Ireland DA - 2011-10-28 PY - 2011 AN - OPUS4-24939 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Development of a PMMA-POF based fiber optic inclinometer with smart transport and installation characteristics T2 - 6th European Workshop on Structural Health Monitoring (EWSHM) CY - Dresden, Germany DA - 2012-06-03 PY - 2012 AN - OPUS4-26456 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Smart Technical Textiles Based on Fibre Optic Sensors - Technologies and Applications T2 - CIMTEC 2012: 4. International Conference "Smart Materials, Structures and Systems" CY - Montecatini Terme, Italy DA - 2012-06-10 PY - 2012 AN - OPUS4-26457 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Fiber Optic Sensors in Technical Safety Sciences T2 - Workshop "Trends in Fiber Optics 2012" CY - Jena, Germany DA - 2012-02-23 PY - 2012 AN - OPUS4-26458 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - POF sensors for structural health monitoring - applications and future demands (invited presentation) T2 - 21st International Conference on Plastic Optical Fibers, POF 2012 CY - Atlanta, GA, USA DA - 2012-09-10 PY - 2012 AN - OPUS4-26792 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Mizuno, Y. A1 - Krebber, Katerina A1 - Nakamura, K. ED - Jaroszewicz, L.R. T1 - L-BOFDA: a new sensor technique for distributed Brillouin sensing N2 - We propose a new scheme of Brillouin optical frequency-domain analysis (BOFDA) for distributed fiber-optic strain and temperature sensing, named linear-configured BOFDA (L-BOFDA). In conventional loop-configured BOFDA, light injection into both ends of a fiber under test (FUT) is needed for counter-propagation of pump and probe waves. In contrast, in L-BOFDA, pump and probe waves are injected into the same end of an FUT, and the probe wave Fresnelreflected (or mirror-reflected) at the other end of the FUT is exploited; thus, one-end access is feasible. We show proof-of-concept results of distributed strain measurement in a silica single-mode fiber with L-BOFDA, and discuss the signal-to-noise ratio degradation and the benefit in developing distributed Brillouin sensors based on polymer optical fibers. T2 - EWOFS 2013 - 5th European workshop on optical fibre sensors CY - Kraków, Poland DA - 19.05.2013 KW - Brillouin optical frequency-domain analysis (BOFDA) KW - L-BOFDA KW - Optical fiber sensing KW - Distributed strain measurement KW - Stimulated Brillouin scattering KW - Polymer optical fiber PY - 2013 DO - https://doi.org/10.1117/12.2025378 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 8794 IS - Paper 8794 - 181 SP - 879431-1 EP - 879431-4 AN - OPUS4-28961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Krebber, Katerina T1 - Application of fiber-optic sensors for health monitoring purposes in geo-engineering T2 - 4th International forum on opto-electronic sensor-based monitoring in geo-engineering CY - Suzhou, China DA - 2012-10-11 KW - BOFDA KW - Fibre-optic sensor KW - Distributed sensor KW - Brillouin sensor KW - Polymer optical fibers (POF) KW - POF sensor KW - POF OTDR KW - Strain sensor KW - Technical textiles KW - Geotextiles KW - Geophone KW - Fabry-Perot sensor KW - Pile test KW - Impact KW - Acoustic wave PY - 2012 SP - 4 EP - 15 AN - OPUS4-27259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Burgmeier, J. A1 - Krebber, Katerina A1 - Schade, Wolfgang T1 - Femtosecond laser structuring of polymer optical fibers for backscatter sensing N2 - Focused femtosecond laser pulses are used to create scattering damage in the core of polymer optical fibers (POF). The resulting structures are investigated regarding morphology by light microscopy and backscattered intensity using optical time domain reflectometry (OTDR). Quasi-distributed optical fiber sensing is proposed by evaluating backscatter changes at the inscribed scatter centers. Application examples for quasi-distributed measurement of fiber bends and temperature are demonstrated. KW - Femtosecond laser KW - Micromachining KW - Optical fiber sensors KW - Polymer optical fiber KW - Polymer PY - 2013 DO - https://doi.org/10.1109/JLT.2013.2250483 SN - 0733-8724 SN - 1558-2213 VL - 31 IS - 9 SP - 1418 EP - 1425 PB - Institute of Electrical and Electronics Engineers CY - New York, NY AN - OPUS4-28733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - POFs for sensing applications N2 - The paper highlights the use of polymer optical fibers (POFs) as sensors in selected applications like structural health monitoring in geotechnical and civil engineering, composites monitoring, healthcare monitoring and personnel protection. The recent progress achieved in this field will be reviewed and the main challenges to these innovative fibre optic sensors will be adressed. T2 - 3rd Workshop on specialty optical fibers and their applications CY - Sigtuna, Sweden DA - 28.08.2013 PY - 2013 IS - T3.6 SP - 1 EP - 2 AN - OPUS4-29334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - POFs for Sensing Applications T2 - Workshop on Specialty Optical fiber and their Applications (WSOF) CY - Sigtuna, Sweden DA - 28.08.2013 PY - 2013 AN - OPUS4-29256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Temperature and humidity discrimination in Brillouin distributed fiber optic sensing using machine learning algorithms N2 - In the last few years, the use of machine learning has emerged in the field of distributed fiber optic sensors as a promising approach to enhance their performance and provide new capabilities. In this study, we use machine learning for simultaneous measurements of temperature and humidity in polyimide (PI)-coated optical fibers based on Brillouin Brillouin optical frequency domain analysis (BOFDA). Different non-linear machine learning algorithms are employed, namely polynomial regression, decision trees and artificial neural networks (ANNs), and their discrimination performance is benchmarked against that of the conventional linear regression. The performance is evaluated using leave-one-out cross-validation to ensure that the models are reliable and able to generalize well on new data. We show that nonlinear machine learning algorithms outperform the conventional linear regression and thus could pave the way towards simultaneous cost-effective temperature and humidity distributed sensing, which has the potential to find attractive new applications in the field of civil and geotechnical engineering, from structural health monitoring of dikes and bridges to subsea cables and long pipelines corrosion detection. T2 - SPIE Photonics Europe 2022 CY - Strasbourg, France DA - 03.04.2022 KW - Distributed Brillouin sensing KW - Machine learning KW - Artificial neural networks KW - Simultaneous temperature and humidity sensing KW - BOFDA PY - 2022 DO - https://doi.org/10.1117/12.2620985 VL - 12139 SP - 1 EP - 7 PB - SPIE AN - OPUS4-54861 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Verteilte faseroptische Sensoren zur Zustandsüberwachung von Verbundwerkstoff-Druckbehältern T1 - Distributed fiber optic sensors for structural health monitoring of composite pressure vessels N2 - In diesem Beitrag geben wir einen umfassenden Überblick über unsere Forschung auf dem Gebiet der verteilten faseroptischen Sensorik für die strukturelle Zustandsüberwachung von Wasserstoffdruckbehältern aus Verbundwerkstoffen. Insbesondere zeigen wir, wie die Integration von faseroptischen Sensoren in Druckbehälter aus Verbundwerkstoffen die Sicherheit erhöht und gleichzeitig die Wartungskosten senkt. Die geringe Größe von Lichtwellenleitern ermöglicht ihre Integration in Verbundwerkstoffstrukturen während des Herstellungsprozesses, wodurch eine kontinuierliche Überwachung sowie eine präzise Erkennung und Lokalisierung von Strukturschäden während des Betriebs der Druckbehälter ermöglicht wird. Wir erörtern auch das Potenzial modernster Signalverarbeitungsmethoden und des maschinellen Lernens für die Weiterentwicklung der vorausschauenden Instandhaltung. Die von uns vorgestellten Anwendungen von faseroptischen Sensoren zeigen, dass sie einen wichtigen Beitrag zur Energiewende hin zu erneuerbaren Energien leisten können. KW - Verteilte faseroptische Sensoren KW - Verbundwerkstoffe KW - Wasserstoff-Druckbehälter KW - Strukturüberwachung KW - Maschinelles Lernen PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596290 DO - https://doi.org/10.1515/teme-2023-0170 SN - 0171-8096 SP - 1 EP - 12 AN - OPUS4-59629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Krebber, Katerina T1 - Monitoring of composite pressure vessels using surface applied distributed fiber optic sensors N2 - In this paper, we report on surface-applied distributed fibre optic sensors for monitoring composite pressure vessels designed for hydrogen storage. Previous reports have revealed that integrating optical fibres within vessel composite structures effectively enables the monitoring of structural behavior throughout their lifetime. However, integrating optical fibres during the manufacturing process is complex and time-consuming. Therefore, we aim to simplify this process by attaching the optical fibres to the vessel’s surface. This method is significantly more timeefficient than the integration process and can be applied to any vessel. Our results demonstrate that surface-applied fibre optic sensors can detect and precisely localise damage. Additionally, signs of damage can be recognised even before the damage occurs. Predictive maintenance using fibre optic sensors could reduce premature maintenance costs and periodic inspections while increasing safety and extending the vessel’s useful service life. The role of machine learning in predictive maintenance is also discussed. T2 - 20th Sensors & their Applications Conference CY - Limerick, Ireland DA - 11.08.2024 KW - Hydrogen KW - Fiber optic sensors KW - Composites KW - Machine learning KW - Structural health monitoring PY - 2024 SP - 1 EP - 4 AN - OPUS4-60911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Woyessa, G. A1 - Schukar, Marcus A1 - Bang, O. A1 - Krebber, Katerina T1 - Response of microstructured plastic optical fiber Bragg grating to gamma radiation N2 - Response of PMMA-based plastic optical fiber Bragg grating (FBG) to gamma radiation is investigated for the first time. FBG wavelength shift as large as 150 pm is observed for irradiation to 18 kGy. T2 - 5th Workshop on specialty optical fibers and their applications CY - Limassol, Cyprus DA - 11.10.2017 KW - Fiber Bragg gratings KW - Optical sensing and sensors KW - Plastic optical fibers KW - Gamma radiation PY - 2017 SP - Poster 19, 1 EP - 2 AN - OPUS4-42586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Großwig, S. A1 - Weber, U. A1 - Krebber, Katerina T1 - Monitoring acoustic events in boreholes using wavelengthscanning coherent optical time domain reflectometry in multimode fiber N2 - A distributed acoustic sensor (DAS) based on wavelength-scanning coherent optical time domain reflectometer (WS-COTDR) is tested in an underground gas storage based on a multimode fiber for the first time to the best of our knowledge. The WS-COTDR acquires the reflection spectrum by scanning the wavelength of the laser and uses the spectra to calibrate strain. It overcomes the fading problem which is common for all DAS systems, and possesses the advantage of simple configuration and low-cost. The working principle of the system is well explained and the measurement results are presented. Various artificial and natural acoustic events have been successfully detected by the WS-COTDR. Such a sensor demonstrates several advantages over the traditional DAS systems, so it is supposed to be widely used in the oil and gas industry. T2 - EAGE GeoTech 2021 Second EAGE Workshop on Distributed Fibre Optic Sensing CY - Online meeting DA - 01.03.2021 KW - Leakage detection KW - Distributed acoustic sensing KW - Distributed fiber optic sensing PY - 2021 DO - https://doi.org/10.3997/2214-4609.202131010 SP - Paper 10, 1 PB - European Association of Geoscientists & Engineers CY - Houten, Niederlande AN - OPUS4-52248 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Großwig, S. A1 - Weber, U. A1 - Krebber, Katerina T1 - Monitoring acoustic events in boreholes using wavelengthscanning coherent optical time domain reflectometry in multimode fiber N2 - A distributed acoustic sensor (DAS) based on wavelength-scanning coherent optical time domain reflectometer (WS-COTDR) is tested in an underground gas storage based on a multimode fiber for the first time to the best of our knowledge. The WS-COTDR acquires the reflection spectrum by scanning the wavelength of the laser and uses the spectra to calibrate strain. It overcomes the fading problem which is common for all DAS systems, and possesses the advantage of simple configuration and low-cost. The working principle of the system is well explained and the measurement results are presented. Various artificial and natural acoustic events have been successfully detected by the WS-COTDR. Such a sensor demonstrates several advantages over the traditional DAS systems, so it is supposed to be widely used in the oil and gas industry. T2 - EAGE GeoTech 2021 CY - Online meeting DA - 01.03.2021 KW - Borehole monitoring KW - Distributed fiber sensing KW - Acoustic sensing PY - 2021 DO - https://doi.org/10.3997/2214-4609.202131010 SP - 1 EP - 5 AN - OPUS4-52152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krebber, Katerina A1 - Weege, S. A1 - Großwig, S. A1 - Obermöller, M. A1 - Perk, M. A1 - Lu, Xin A1 - Schukar, Marcus A1 - Weber, U. A1 - Pfeiffer, T. A1 - Rembe, M. T1 - Kombinierte faseroptische Messungen in Bohrlöchern helfen bei der Detektion von Kleinstleckagen N2 - Seit November 2019 läuft ein breit angelegtes und vom BMWi gefördertes ZIM-Kooperationsprojekt zwischen der Bundesanstalt für Materialforschung und -prüfung (BAM), der IAB'Weimar gGmbH, der GKSO GmbH & Co. Projekt KG, der DEEP.KBB GmbH sowie der Rembe Consulting PartG mbB. Ziel des Forschungsvorhabens sind sowohl die Lokalisierung als auch die Quantifizierung insbesondere sehr kleiner Leckagen in einer Bohrlochverrohrung durch die Nutzung faseroptischer Messtechnik. Durch Messdatenkopplung und den Wegfall bewegungsbedingter Nachteile einer Messsonde werden wesentlich präzisere Ergebnisse zur Bewertung der Bohrlochintegrität als üblich erwartet. T2 - DGMK/ÖGEW-Frühjahrstagung 2020 CY - Meeting was canceled DA - 15.04.2020 KW - Wasserstoffspeicher KW - Kavernenspeicher KW - Verteilte faseroptische akustische Sensorik PY - 2020 VL - 6 SP - 43 EP - 43 PB - DVV Media Group CY - Hamburg AN - OPUS4-52233 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Characterizing vibration response of fiber cables for distributed acoustic sensing N2 - The vibration responses of two fiber cables are characterized up to 16 kHz and compared with a standard tight-buffered 900 um fiber. The response of the cables is suppressed due to the cable protection. T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Distributed fiber sensing KW - Acoustic sensing KW - Response characterization PY - 2022 AN - OPUS4-56099 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Weege, S. A1 - Roske, T. A1 - Krebber, Katerina T1 - Leakage detection at a borehole simulator using distributed acoustic sensing N2 - A distributed acoustic sensing system is used to detect the leakage in a borehole simulator by measuring the leakage induced vibration. The leakage location can be clearly determined by frequency spectrum analysis. T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Leakage detection KW - Structural health monitoring KW - Distributed fiber sensing KW - Distributed acoustic sensing PY - 2022 SP - 1 EP - 4 PB - Optica CY - Washington D.C., USA AN - OPUS4-56097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Characterizing vibration response of fiber cables for distributed acoustic sensing N2 - The vibration responses of two fiber cables are characterized up to 16 kHz and compared with a standard tight-buffered 900 um fiber. The response of the cables is suppressed due to the cable protection T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Response characterization KW - Distributed fiber sensing KW - Acoustic sensing PY - 2022 SP - 1 EP - 4 PB - Optica CY - Washington D.C., USA AN - OPUS4-56096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Weege, S. A1 - Roske, T. A1 - Krebber, Katerina T1 - Leakage detection at a borehole simulator using distributed acoustic sensing N2 - A distributed acoustic sensing system is used to detect the leakage in a borehole simulator by measuring the leakage induced vibration. The leakage location can be clearly determined by frequency spectrum analysis. T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Structural health monitoring KW - Distributed fiber sensing KW - Distributed acoustic sensing KW - Leakage detection PY - 2022 AN - OPUS4-56098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Popiela, Bartosz A1 - Günzel, Stephan A1 - Schukar, Marcus A1 - Mair, Georg W. A1 - Krebber, Katerina A1 - Seidlitz, Holger T1 - Impact of internal pressure control during manufacturing on residual stresses and safety performance of type 4 pressure vessels N2 - Composite pressure vessels are commonly manufactured using the wet filament winding process, where various process parameters can influence the performance of the finished component. In this study two designs of wet filament wound 6.8-liter type 4 composite pressure vessels were manufactured. Both differ only by the internal pressure used during the filament winding, which primarily influences the residual stress state in the composite structure. An extensive experimental study was carried out, including 10 slow burst tests and strain measurements with fiber optic sensors. Significant differences can be observed in the performance of the two designs even though the used stacking sequence, materials and other manufacturing parameters are the same for both designs. A discussion of the differences in the behavior of both cylinder types is provided, including the strain distribution in slow burst tests and failure mechanism. KW - Residual stresses KW - Slow burst tests KW - Filament winding KW - Type 4 composite pressure vessels KW - Hydrogen PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626663 DO - https://doi.org/10.1016/j.jcomc.2025.100581 SN - 2666-6820 VL - 17 SP - 1 EP - 9 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-62666 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Glötzl, R. ED - Boller, C. T1 - Development of a PMMA-POF based fiber optic inclinometer with smart transport and installation characteristics N2 - We present the state of our work concerning the development of a fiber optic inclinometer based on PMMA POF which provides distributed sensitivity regarding level, direction and location of deformation within critical ground structures. According to the demand for simple less expensive Installation and Operation of reliable sensor Systems a sensor concept has been developed and to our knowledge the first results of a PMMA POF based inclinometer prototype are presented in the following chapters. T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 03.07.2012 PY - 2012 SN - 978-3-940283-41-2 IS - Chapt. Optical Sensors SP - 411 EP - 416 CY - Berlin AN - OPUS4-26193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wendt, Mario A1 - Krebber, Katerina T1 - Using optical POF switches for distributed fiber optical strain measurements N2 - During recent research projects FOS sensor Systems based on PMMA (see fig.l) and perfluorined POF have been developed in order to observe critical earth structures [1,2], The sensor Systems enables real distributed Observation of objects due to the use of OTDR technique, whereas an increased Rayleigh backscatter level is observed at the strained fiber section. Fürther both used POF types are very robust which makes the sensor System suitable for harsh environment condilions and secure continuous measurements even within strong deformed structures. These characteristics offer opportunities to complement the arsenal of established electric based sensor Systems. However, due to high cost of OTDR devices the developed sensor System is not ready for the market yet. To make an improvement here the feasibility of optical switches have been investigated in order to use multiple single sensor lines connected to one OTDR device. Despite to the fact that optical switches are established in the field of telecommunication the use for distributed optical measurements is to our knowledge not investigated yet. One question which has to be answered is if strong reflections which occur at fiber couplings disable the Signals of the single sensor lines. A further interest is to secure that the known sensing characteristics of the single System is still provided via optical switch. For this purpose two optical switches each adapted to PMMA and perfluorined characteristics respectively have been tested. Laboratory tests have been conducted, whereas two OTDR units for PMMA and perfluorined POF were available. Finally the switches have been tested during field tests. T2 - POF 2012 - 21st International conference on plastic optical fibers CY - Atlanta, Georgia, USA DA - 10.09.2012 KW - Distributed strain sensors KW - Optical switch KW - OTDR PY - 2012 SP - 133 EP - 136 AN - OPUS4-26743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -