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 - JOUR A1 - Kapa, Thomas A1 - Schreier, Andy A1 - Krebber, Katerina T1 - 63 km BOFDA for temperature and strain monitoring N2 - We demonstrate (and are the first to do so) 63 km Brillouin Optical Frequency-Domain Analysis (BOFDA) for temperature and strain monitoring using a 100 km fiber loop. The use of BOFDA for long-range applications can be considered a novel approach, as previous investigations focused on the utilization of Brillouin Optical Time-Domain Reflectometry and Analysis (BOTDR and BOTDA, respectively). At 51.7 km, a 100 m hotspot (37 °C) was detected without using distributed Raman amplification or image processing. KW - Distributed sensing KW - Stimulated Brillouin scattering KW - Fiber optics sensors PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-449679 SN - 1424-8220 VL - 18 IS - 5 SP - 1600, 1 EP - 9 PB - MDPI CY - Basel, Switzerland AN - OPUS4-44967 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kapa, Thomas A1 - Schreier, Andy A1 - Krebber, Katerina T1 - A 100-km BOFDA Assisted by First-Order Bi-Directional Raman Amplification N2 - We present, to our knowledge for the first time, a 100-km Brillouin Optical Frequency-Domain Analysis (BOFDA) employing a 200-km fiber loop. Compared to our previous publication, enhanced sensor length, sensor accuracy and spatial resolution are presented. The performance improvements are achieved by applying distributed Raman amplification (DRA) and a digital high-pass filter. We report on temperature measurements over sensing distances of 75 km and 100 km both with a 12.5-m spatial resolution. Temperature changes of 5 °C have been measured along 75 km sensing fiber. A temperature change of 30 °C has been detected at 99.5 km. KW - Distributed sensing KW - Fiber optics sensors KW - Stimulated Brillouin scattering PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-476577 SN - 1424-8220 VL - 19 IS - 7 SP - 1527, 1 EP - 9 PB - MDPI CY - Basel, Switzerland AN - OPUS4-47657 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 - 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 U6 - 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 - 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 - 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 U6 - 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 - 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 U6 - 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 - 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 U6 - 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 - 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 U6 - 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 -