TY - CONF A1 - Lenke, Philipp T1 - Improvement of the distributed strain sensor based on optical time domain reflectometry measurement in polymer optical fibers T2 - 17. Conference on polymer optical fiber CY - Santa Clara, CA, USA DA - 2008-08-26 PY - 2008 AN - OPUS4-17777 LA - deu 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 - 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 - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Witt, Jens A1 - Schukar, Marcus A1 - Large, M. A1 - Thiel, T. T1 - Technology and Applications of Smart Technical Textiles Based on POF T2 - 17th International Conference on Plastic Optical Fibers (POF 2008), August 25-28, 2008 CY - Santa Clara, California, USA DA - 2008-08-25 KW - Fiber optic sensors KW - Polymer optical fibers (POF) KW - POF sensors KW - Smart technical textiles PY - 2008 SP - 1 EP - 10 AN - OPUS4-17870 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp T1 - Technology and applications of smart technical textiles based on POF T2 - Invited Paper, Proceed. of 17th International Conference on POF, Santa Clara, California CY - Santa Clara, CA, USA DA - 2008-08-26 PY - 2008 AN - OPUS4-17776 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -