TY - JOUR A1 - Karapanagiotis, Christos A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Eine Sammlung durch Maschinelles Lernen unterstützter Verteilter Faseroptischer Sensoren für Infrastrukturmonitoring T1 - A collection of machine learning assisted distributed fiber optic sensors for infrastructure monitoring N2 - In this paper, we present a collection of machine learning assisted distributed fiber optic sensors (DFOS) for applications in the field of infrastructure monitoring. We employ advanced signal processing based on artificial neural networks (ANNs) to enhance the performance of the dynamic DFOS for strain and vibration sensing. Specifically, ANNs in comparison to conventional and computationally expensive correlation and linearization algorithms, deliver lower strain errors and speed up the signal processing allowing real time strain monitoring. Furthermore, convolutional neural networks (CNNs) are used to denoise the dynamic DFOS signal and enable useable sensing lengths of up to 100 km. Applications of the machine learning assisted dynamic DFOS in road traffic and railway infrastructure monitoring are demonstrated. In the field of static DFOS, machine learning is applied to the well-known Brillouin optical frequency domain analysis (BOFDA) system. Specifically, CNN are shown to be very tolerant against noisy spectra and contribute towards significantly shorter measurement times. Furthermore, different machine learning algorithms (linear and polynomial regression, decision trees, ANNs) are applied to solve the well-known problem of cross-sensitivity in cases when temperature and humidity are measured simultaneously. The presented machine learning assisted DFOS can potentially contribute towards enhanced, cost effective and reliable monitoring of infrastructures. N2 - In diesem Beitrag stellen wir eine Sammlung von verteilten faseroptischen Sensoren (DFOS) vor, die mit Hilfe von Maschinellem Lernen arbeiten und für Anwendungen im Bereich der Infrastrukturüberwachung geeignet sind. Wir setzen hierbei fortschrittliche Signalverarbeitung auf der Grundlage Künstlicher Neuronaler Netze ein, um die Leistungsfähigkeit dynamischer DFOS für die Messung von Dehnungen und Vibrationen zu verbessern. Insbesondere Künstliche Neuronale Netze (ANNs) liefern im Vergleich zu konventionellen und rechenintensiven Korrelations- und Linearisierungsalgorithmen geringere Dehnungsfehler und beschleunigen die Signalverarbeitung, so dass eine Dehnungsüberwachung in Echtzeit möglich ist. Darüber hinaus wenden wir Convolutional Neural Networks (CNNs) an, um dynamische DFOS-Signale zu entrauschen und damit nutzbare Messlängen von bis zu 100 km zu ermöglichen. Es werden Anwendungsbeispiele dieser durch Maschinelles Lernen unterstützten dynamischen DFOS in den Bereichen des Straßenverkehrsmonitorings und der Zug- und Gleisüberwachung aufgezeigt. Im Bereich der statischen DFOS wird Maschinelles Lernen auf das Verfahren der Optischen Brillouin-Frequenzbereichsanalyse (BOFDA) angewendet. Insbesondere CNN erweisen sich hier als sehr robust gegenüber verrauschten Spektren und tragen zu deutlich kürzeren Messzeiten bei. Darüber hinaus werden verschiedene Algorithmen des maschinellen Lernens (lineare und polynome Regression, Entscheidungsbäume, ANNs) angewandt, um das bekannte Problem der Querempfindlichkeit bei DFOS in den Fällen zu lösen, in denen Temperatur und Feuchtigkeit gleichzeitig gemessen werden sollen. Die hier vorgestellten, durch Maschinelles Lernen unterstützten, DFOS können zu einer verbesserten, kostengünstigen und zuverlässigen Überwachung von Infrastrukturen beitragen. KW - Artificial neural networks KW - Brillouin sensing KW - Distributed acoustic sensing KW - Fibre optic sensors KW - Infrastructure monitoring PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569044 DO - https://doi.org/10.1515/teme-2022-0098 SN - 0171-8096 SP - 1 EP - 19 PB - De Gruyter AN - OPUS4-56904 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Krebber, Katerina T1 - Machine Learning Approaches in Brillouin Distributed Fiber Optic Sensors N2 - This paper presents reported machine learning approaches in the field of Brillouin distributed fiber optic sensors (DFOSs). The increasing popularity of Brillouin DFOSs stems from their capability to continuously monitor temperature and strain along kilometer-long optical fibers, rendering them attractive for industrial applications, such as the structural health monitoring of large civil infrastructures and pipelines. In recent years, machine learning has been integrated into the Brillouin DFOS signal processing, resulting in fast and enhanced temperature, strain, and humidity measurements without increasing the system’s cost. Machine learning has also contributed to enhanced spatial resolution in Brillouin optical time domain analysis (BOTDA) systems and shorter measurement times in Brillouin optical frequency domain analysis (BOFDA) systems. This paper provides an overview of the applied machine learning methodologies in Brillouin DFOSs, as well as future perspectives in this area. KW - Distributed fiber optic sensors KW - BOTDA KW - BOFDA KW - Machine learning KW - Strain and temperature measurements KW - Artificial neural networks PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580145 DO - https://doi.org/10.3390/s23136187 VL - 23 IS - 13 SP - 1 EP - 26 PB - MDPI AN - OPUS4-58014 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Machine learning assisted BOFDA for simultaneous temperature and strain sensing in a standard optical fiber N2 - We report, to our knowledge for the first time on simultaneous distributed temperature and strain sensing in a standard telecom optical fiber using a machine learning assisted Brillouin frequency domain analysis (BOFDA) system. The well-known temperature and strain cross-sensitivity problem is addressed by developing a BOFDA system with a high signal-to-noise ratio and applying machine learning. The spectrum consists of four highly resolved peaks, whose Brillouin frequency shifts are extracted and serve as features for the machine learning algorithms. The spectra result from a 450-m standard SMF-28 optical fiber, and particularly from a segment of 30 m. This fiber segment is coiled around a stretcher and placed in a climate chamber. The applied temperature and strain values range from 20 °C to 40 °C and from 0 µɛ to 1380 µɛ, respectively. The total measurement time to achieve a high SNR and resolve four peaks with a spatial resolution of 6 m is 16 min. To discriminate temperature and strain effects, simple frequentist and more sophisticated Bayesian-based algorithms are employed with the powerful Gaussian process regression (GPR) delivering the best performance in terms of temperature and strain errors, which are found to be 2 °C and 45 µɛ, respectively. These errors are calculated using leave-one-out cross-validation, so that an unbiased estimation of the sensor’s performance is provided. KW - Machine learning KW - Brillouin distributed fiber optic sensors KW - Temperature and strain sensing KW - BOFDA PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569155 DO - https://doi.org/10.1364/OE.480224 SN - 1094-4087 VL - 31 IS - 3 SP - 5027 EP - 5041 PB - OPTICA AN - OPUS4-56915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Wosniok, Aleksander A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Time-Efficient Convolutional Neural Network-Assisted Brillouin Optical Frequency Domain Analysis N2 - To our knowledge, this is the first report on a machine-learning-assisted Brillouin optical frequency domain analysis (BOFDA) for time-efficient temperature measurements. We propose a convolutional neural network (CNN)-based signal post-processing method that, compared to the conventional Lorentzian curve fitting approach, facilitates temperature extraction. Due to its robustness against noise, it can enhance the performance of the system. The CNN-assisted BOFDA is expected to shorten the measurement time by more than nine times and open the way for applications, where faster monitoring is essential. KW - Fiber-optic sensors KW - Machine learning KW - Temperature and strain monitoring KW - Brillouin distributed sensing PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524631 DO - https://doi.org/10.3390/s21082724 VL - 21 IS - 8 SP - 2724 PB - MDPI AN - OPUS4-52463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Hicke, Konstantin A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed humidity fiber-optic sensor based on BOFDA using a simple machine learning approach N2 - We report, to our knowledge for the first time, on distributed relative humidity sensing in silica polyimide-coated optical fibers using Brillouin optical frequency domain analysis (BOFDA). Linear regression, which is a simple and well-interpretable algorithm in machine learning and statistics, is utilized. The algorithm is trained using as features the Brillouin frequency shifts and linewidths of the fiber’s multipeak Brillouin spectrum. To assess and improve the effectiveness of the regression algorithm, we make use of machine learning concepts to estimate the model’s uncertainties and select the features that contribute most to the model’s performance. In addition to relative humidity, the model is also able to simultaneously provide distributed temperature information addressing the well-known cross-sensitivity effects. KW - Fiber optics sensors KW - Machine learning KW - Brillouin distributed sensing KW - Humidity sensing KW - Simultaneous temperature and humidity sensing PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546294 DO - https://doi.org/10.1364/OE.453906 VL - 30 IS - 8 SP - 12484 EP - 12494 PB - OPTICA AN - OPUS4-54629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Multiscale reinforcement of Semi-Crystalline Thermoplastic Sheets and Honeycombs (M-RECT) T2 - ITHEC 2014, 2nd International Conference and Exhibition on Thermoplastic Composites CY - Bremen, Germany DA - 2014-10-27 PY - 2014 AN - OPUS4-32029 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reiche, T. A1 - Teichmann, H. A1 - Krebber, Katerina A1 - Salomon, O. A1 - Wood, A. T1 - Multiscale reinforcement of semi-crystalline thermoplastic sheets and honeycombs (M-RECT) N2 - M-RECT was a European FP7 funded project investigating multiscale reinforced thermoplastic composites. The project involved the functionalisation of carbon nanotubes (CNT) with a view to: • Improving their performance and ease of dispersion • Improving the damping characteristics of composites • Evaluating the mechanical performance of CNT reinforced laminates • Developing modelling Software for the design of materials and components • Developing sensor Systems to provide feedback on the local strains within such composites This presentation seeks to provide a general overview of the results from the project with particular emphasis T2 - ITHEC 2014 - 2nd International Conference and Exhibition on Thermoplastic Composites CY - Bremen, Germany DA - 27.10.2014 KW - Carbon nanotubes KW - Multiscale thermoplastic-matrix composites KW - Modelling PY - 2014 SN - 978-3933339256 SP - 12 EP - 15 AN - OPUS4-32353 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Fiber Optic Sensors for SHM - From Laboratory to Industrial Applications (invited lecture) T2 - OSA Conference "Applied Industrial Optics: Spectroscopy, Imaging and Metrology (AIO)" CY - Seattle, WA, USA DA - 2014-07-13 PY - 2014 AN - OPUS4-31131 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Nöther, N. A1 - Steffen, Milan A1 - Gili, O. A1 - Krebber, Katerina ED - López-Higuera, J.M. ED - Jones, J. ED - López-Amo, M. ED - Santos, J.L. T1 - Performance of digital incoherent OFDR and prospects for optical fiber sensing applications N2 - We propose a digital implementation of the incoherent optical frequency domain reflectometry (I-OFDR) technique for precise backscatter measurement and optical fiber sensing applications. Specific performance parameters of the I-OFDR are discussed and compared to an analog vector network analyzer-based I-OFDR system. Improved sensitivity, dynamic range and signal stability of the digital I-OFDR is presented and demonstrated by means of quasi-distributed length change measurement. T2 - OFS2014 - 23rd International conference on optical fibre sensors CY - Santander, Spain DA - 02.06.2014 KW - Optical fiber sensors KW - Backscatter measurement KW - Strain sensor KW - OFDR KW - OTDR PY - 2014 DO - https://doi.org/10.1117/12.2059639 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 9157 SP - 915737-1 EP - 915737-4 AN - OPUS4-30899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Fiber optic sensors for SHM - from laboratory to industrial applications N2 - The paper highlights the research activities in Germany and Europe in the development of distributed fiber optic sensor for structural health monitoring (SHM) like the monitoring of geotechnical and civil infrastructures and presents selected results achieved within these projects. T2 - OSA Optics & photonics congress - Imaging and applied optics CY - Seattle, Washington, USA DA - 13.07.2014 PY - 2014 SN - 978-1-55752-308-2 DO - https://doi.org/10.1364/AIO.2014.AM4A.1 SP - 1 EP - 2 AN - OPUS4-31195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Muanenda, Y. S. A1 - Münzenberger, Sven A1 - Krebber, Katerina T1 - Relative change measurement of physical quantities using dual-wavelength coherent OTDR N2 - We propose the use of alternating pulse wavelengths in a direct-detection coherent optical time domain reflectometry (C-OTDR) setup not only to measure strain and temperature changes but also to determine the correct algebraic sign of the change. The sign information is essential for the intended use in distributed mode shape analysis of civil engineering structures. Correlating relative backscatter signal shifts in the temporal/signal domain allows for measuring with correct magnitude and sign. This novel approach is simulated, experimentally implemented and demonstrated for temperature change measurement at a spatial resolution of 1 m. KW - Fiber optics sensors KW - Backscattering KW - Rayleigh KW - C-OTDR KW - Distributed sensing KW - Temperature measurement KW - Strain measurement PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-389449 DO - https://doi.org/10.1364/OE.25.000720 SN - 1094-4087 VL - 25 IS - 2 SP - 720 EP - 729 PB - Optical Society of America CY - Washington, DC, USA AN - OPUS4-38944 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin A1 - Krebber, Katerina ED - Chung, Y. ED - Jin, W. ED - Lee, B. ED - Canning, J. ED - Nakamura, K. ED - Yuan, L. T1 - Towards efficient real-time submarine power cable monitoring using distributed fibre optic acoustic sensors N2 - Online condition monitoring of submarine power cables helps to avert failures and damages produced by mechanical impacts. We report, to our knowledge for the first time, on investigations regarding the feasibility of distributed fiber optic acoustic sensors based on C-OTDR, with the sensor fibres being embedded in the cable, to detect vibrations due to mechanical disturbances along the cable. We present first results of sensing experiments where acoustic signals are transmitted through water to simulate the corresponding submarine conditions. Furthermore, we show results evaluating the usefulness of fibre commonly embedded in existing power cable designs for our sensing purposes. T2 - 25th International Conference on Optical Fiber Sensors CY - Jeju-City, Jeju, Republic of Korea DA - 24.04.2017 KW - Distributed acoustic sensing KW - Power cable monitoring KW - C-OTDR KW - Fibre optic sensors KW - DAS PY - 2017 SN - 978-1-5090-4850-2 DO - https://doi.org/10.1117/12.2267474 SN - 0277-786X SN - 1996-756X VL - 10323 SP - 1032390-1 EP - 1032390-4 PB - SPIE CY - Bellingham, WA, USA AN - OPUS4-40088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin A1 - Hussels, Maria-Teresa A1 - Eisermann, René A1 - Chruscicki, Sebastian A1 - Krebber, Katerina ED - Chung, Y. ED - Jin, W. ED - Lee, B. ED - Canning, J. ED - Nakamura, K. ED - Yuan, L. T1 - Condition monitoring of industrial infrastructures using distributed fibre optic acoustic sensors N2 - Distributed fibre optic acoustic sensing (DAS) can serve as an excellent tool for real-time condition Monitoring of a variety of industrial and civil infrastructures. In this paper, we portray a subset of our current Research activities investigating the usability of DAS based on coherent optical time-domain reflectometry (C-OTDR) for innovative and demanding condition Monitoring applications. Specifically, our application-oriented Research presented here aims at acoustic and vibrational condition monitoring of pipelines and piping systems, of rollers in industrial heavy-duty conveyor belt systems and of extensive submarine power cable installations, respectively. T2 - 25th International Conference on Fiber Optic Sensors CY - Jeju-City, Jeju, Republic of Korea DA - 24.04.2017 KW - Condition monitoring KW - Distributed fibre optic acoustic sensing KW - Fibre optic sensors KW - Industrial monitoring KW - DAS PY - 2017 SN - 978-1-5090-4850-2 DO - https://doi.org/10.1117/12.2272463 SN - 0277-786X SN - 1996-756X VL - 10323 SP - 103230J-1 EP - 103230J-4 PB - SPIE CY - Bellingham, WA, USA AN - OPUS4-40091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin A1 - Hussels, Maria-Teresa A1 - Eisermann, René A1 - Chruscicki, Sebastian A1 - Krebber, Katerina T1 - Distributed Fibre Optic Acoustic and Vibration Sensors for Industrial Monitoring Applications N2 - We investigate the usability of distributed fibre optic acoustic sensing (DAS) for innovative and advanced monitoring applications in industrial and civil infrastructure installations. In this paper, we report on our ongoing application-oriented research activities regarding the utilization of DAS based on coherent optical time-domain reflectometry (C-OTDR) for condition monitoring of a variety of infrastructures. Specifically, our research presented here aims at acoustic condition monitoring of and fault detection in pipelines and industrial piping systems, at acoustic condition monitoring of rollers in industrial conveyor belt installations, and at acoustic condition monitoring of and threat detection in extensive submarine power cables, respectively. Furthermore, we show a method to mitigate the effect of sensitivity fading of C-OTDR based DAS due to unstable environmental conditions via the modification of the sensor fibre. This can help to provide a continuous adequate sensor functionality for a number of different industrial monitoring applications. T2 - SENSOR 2017 - 18th International Conference on Sensors and Measurement Technology CY - Nuremberg, Germany DA - 30.05.2017 KW - distributed acoustic sensing KW - fibre optic sensors KW - condition monitoring KW - industrial monitoring KW - C-OTDR PY - 2017 SN - 978-3-9816876-4-4 DO - https://doi.org/10.5162/sensor2017/B7.3 SP - 274 EP - 279 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-40473 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Krebber, Katerina ED - Webb, D. J. ED - Scully, P. ED - Sugden, K. T1 - Radiation induced attenuation in perfluorinated polymer optical fibres for dosimetry applications N2 - Real-time measurement of radiation-induced attenuation (RIA) in a commercial perfluorinated polymer optical fibre (PF-POF) is performed with regard to on-line Radiation monitoring purposes. Spectral character and dose dependence of fibre’s RIA is measured in 450-900 nm spectral region. Fibre exhibited high radiation sensitivity in the visible region with strong increase towards the UV wavelengths. Good linearity and high sensitivity reaching up to 130 dBm-1/kGy was demonstrated in the VIS region for a low-dose range. This of-the-shelf PF-POF could be therefore interesting for on-line remote dosimetry applications. T2 - POF 2016: 25th International Conference on Plastic Optical Fibres CY - Birmingham, UK DA - 13.09.2016 KW - Perfluorinated polymer optical fibers KW - Gamma radiation monitoring KW - Radiation induced attenuation PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-403221 SN - 978-1-85449-408-5 SP - 167 EP - 170 CY - Birmingham AN - OPUS4-40322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Krebber, Katerina ED - Chung, Y. ED - Jin, W. ED - Lee, B. ED - Canning, J. ED - Nakamura, K. ED - Yuan, L. T1 - Towards on-line radiation monitoring with perfluorinated polymer optical fibers N2 - Sensitivity of two commercial perfluorinated (PF) polymer optical fibers (POFs) to gamma radiation was measured, compared and exploited for dosimetry purposes. Fiber radiation induced attenuation (RIA) was found to be highly wavelength dependent and pronounced towards the UV part of the spectrum. PF-POFs were shown to be highly radiation sensitive and RIA-based on-line radiation monitoring with sensitivity as high as 135 dBm-1/kGy was demonstrated at 460 nm with co-extruded PF-POF. In addition, thanks to low inherent attenuation in the near-infrared region, possibility of distributed radiation detection with PF-POFs was demonstrated for the first time, utilizing optical time domain reflectometry. T2 - 25th International Conference on Optical Fiber Sensors CY - Jeju, Republic of Korea DA - 24.04.2017 KW - Radiation-induced attenuation KW - Perfluorinated polymer optical fibers KW - Cytop KW - Gamma radiation KW - Optical fiber dosimetry KW - Optical fiber sensors KW - Distributed radiation sensing PY - 2017 SN - 978-1-5090-4850-2 DO - https://doi.org/10.1117/12.2256354 SN - 0277-786X SN - 1996-756X VL - 10323 SP - 103231O-1 EP - 103231O-4 PB - SPIE AN - OPUS4-40323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Sporea, D. A1 - Neguţ, D. A1 - Krebber, Katerina T1 - Gamma radiation influence on silica optical fibers measured by optical backscatter reflectometry and Brillouin sensing technique N2 - We have studied the influence of gamma rays on physical properties of different commercially available silica optical fibers stepwise irradiated up to a total dose of 100 kGy. The detection of radiation-induced changes in silica glass offers the possibility of using selected optical fibers as distributed radiation sensors. The measurements performed by us were based on optical backscatter reflectometry and Brillouin distributed sensing. The measurement methods enable an analysis of radiation-induced modification of the group refractive index and density of the optical fibers. The most distinct physical effect observed by us concerns the increase of the optical attenuation with rising total radiation doses. Quantitative measurement results indicate a crucial impact of fiber dopants on radiation-induced physical and sensory characteristics of silica optical fibers affected by differences in fiber fabrication techniques. Based on the obtained results, the suitability of distributed Brillouin sensing for dosimetry applications seems to be improved by modifying the refractive index profile of the fiber core. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, IRL DA - 31.05.2016 KW - Brillouin frequency shift KW - Lonizing radiation KW - Gamma radiation KW - Radiation dosimetry KW - Optical fiber sensor KW - Brillouin scattering KW - Distributed measurement KW - Backscatter reflectometry PY - 2016 SN - 978-1-5106-0219-9 DO - https://doi.org/10.1117/12.2236678 SN - 0277-786X VL - 9916 SP - Article Number: 99162J PB - Spie-Int Soc Optical Engineering CY - Bellingham, WA, USA AN - OPUS4-37083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Habel, Wolfgang R. A1 - Krebber, Katerina A1 - Daum, Werner T1 - Results in standardization of FOS to support the use of SHM systems N2 - Measurement and data recording systems are important parts of a holistic Structural Health Monitoring (SHM) system. New sensor technologies such as fiber-optic sensors are often used; however, standards (or at least guidelines) are not yet available or internationally approved. This lack in standardization makes the acceptance of FOS technologies in complex SHM systems substantially difficult. A standard family for different FOS technologies is therefore being developed that should help to design SHM systems in an optimal way. International standardization activities take place in several standardization bodies such as IEC and ASTM, and within SHM societies such as ISHMII. The paper reports on activities in standardization of fiber-optic sensors, on results already achieved, and on newly started projects. Combined activities of fiber sensor experts and SHM experts from Civil Engineering are presented. These contributions should help owners of structures as well as developers of sensors and monitoring systems to select effective and validated sensing technologies. Using these standards, both parties find recommendations how to proceed in development of SHM systems to evaluate the structural behavior based on e.g. standardized fiber optic sensors, and to derive necessary measures, e.g. the optimal maintenance strategy. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, Ireland DA - 30.05.2016 KW - Fiber-optic sensor KW - Standard KW - Temperature KW - Strain KW - Monitoring KW - Structural health KW - Application PY - 2016 DO - https://doi.org/10.1117/12.2236863 SN - 0277-786X VL - 9916 SP - 991625-1 EP - 991625-4 AN - OPUS4-37053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Phase-OFDR for Distributed Disturbance Measurement N2 - We introduce the optical frequency domain reflectometry (OFDR) technique based on intensity modulation frequency sweep measurement for distributed disturbance measurement in optical fibres. By evaluating interferometric Rayleigh scattering changes along the fibre, strain and temperature changes are detected with 100 nε sensitivity and 10 mK resolution. The vibration frequencies for low frequencies and up to the kHz-range can be obtained from power change Evaluation in the spatial domain. This novel OFDR approach is a low-cost alternative for distributed disturbance measurement up to distances of several kilometres. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, Ireland DA - 31.05.2016 KW - Temperature sensing KW - OFDR KW - Distributed sensor KW - Rayleigh scattering KW - Strain measurement PY - 2016 UR - http://proceedings.spiedigitallibrary.org/conferenceproceedings.aspx DO - https://doi.org/doi:10.1117/12.2236851 SN - 0277-786X VL - Vol. 9916 SP - Paper 991624, 4 PB - SPIE CY - Bellingham, Washington USA AN - OPUS4-37228 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Applications and prospects for distributed sensing using polymer optical fibres N2 - One of the unique advantages of polymer optical fibres (POF) is that they can be used to measure very high strain values up to 100 % and beyond exceeding the strain limits of silica fibre-based sensor principles. In this paper the distributed strain measurement capabilities of POF based on backscatter change evaluation are summarized and distributed backscatter measurement technologies are intro-duced. Application examples in the structural health monitoring (SHM) field are presented: a promising approach is the integration into technical textiles for high-strain measurement in earthwork structures and crack detection in buildings. The potential of POF for future applications in SHM such as distributed relative humidity sensing is discussed. T2 - International Conference on Smart Infrastructure and Construction CY - Cambridge, UK DA - 27.06.2016 KW - Strain measurement KW - Structural health monitoring KW - OTDR KW - Polymer Optical Fibre KW - Distributed sensing PY - 2016 UR - http://www.icevirtuallibrary.com/doi/abs/10.1680/tfitsi.61279.093 SN - 978-0-7277-6127-9 DO - https://doi.org/10.1680/tfi tsi.61279.093 SP - 93 EP - 98 PB - ICE Publishing CY - London, UK AN - OPUS4-37230 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hofmann, Detlef A1 - Krebber, Katerina ED - Lutz, B. ED - Möller, G. ED - Rücker, Werner ED - Schiefelbein, N. T1 - Herausforderungen bei der Nutzung faseroptischer Sensoren für spezielle geotechnische Fragestellungen N2 - Geotechnische Tätigkeitsfelder und Forschungsaufgaben haben sich immer an den modernen Herausforderungen orientiert und umfassen z. B. die Beschreibung und Quantifizierung der Interaktion zwischen Baugrund und Bauwerk, die Untersuchung des Untergrunds besonders hinsichtlich der technischen und sozialen Infrastrukturen und die Beeinflussung der Umwelt. Fragen der zivilen Sicherheit stellen steigende Anforderungen an die Tragfähigkeit und Dauerhaftigkeit von Bauwerken. Zur Lösung dieser Aufgaben entstehen vielfältige interessante Methoden und Verfahren zur Strukturbewertung, die neben der Erfassung des allgemeinen Zustands auch neue Erkenntnisse zum Bauwerksverhalten im Hinblick auf moderne Bautechnologien und auf die Lebensdauer von Bauwerken liefern. Die systematische, zuverlässige und langzeitstabile Erfassung von geotechnischen Messgrößen und Parametern bei der Strukturbewertung sowie die Beobachtung und Bewertung der geologischen Gegebenheiten mit technischen Hilfsmitteln ist dafür unerlässlich und lässt sich mit den Begriffen Zustandsanalyse und Bauwerksmonitoring zusammenfassen. Das Ziel dabei ist, mögliche Schädigungsmechanismen frühzeitig zu erkennen, um rechtzeitig Gegenmaßnahmen ergreifen zu können. T2 - Messen im Bauwesen 2014 - Neue Messtechniken und Anwendungsfälle CY - Berlin, Germany DA - 04.03.2014 KW - Faseroptische Sensorik KW - Optische Messverfahren KW - Fabry-Perot-Interferometer KW - Faser-Bragg-Gitter KW - Applikation KW - Anwendungen KW - Geomatten KW - Raman KW - Brillouin PY - 2014 SN - 978-3-9815944-7-8 SP - 7 EP - 26 AN - OPUS4-33812 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Krebber, Katerina A1 - Daum, Werner ED - Peters, K.J. T1 - Standardization in fibre-optic sensing for structural safety - activities in the ISHMII and IEC N2 - Fiber-optic sensors are increasingly established in the sensor market. Their advantages have unquestionably been verified by numerous demonstrations to enhance the operational performance of aged structures or to monitor the structural behavior of safety-relevant structures or their components. However, there are some barriers in use due to a lack of extensive standardization of fiber-optic sensors. This leads very often to restraints in the user’s community. The paper shows the status in international standardization of fiber-optic sensors as well as current activities in leading institutions such as IEC and ISHMII and others with the purpose of providing relevant standards for a broader use of selected fiber-optic sensor technologies. T2 - Smart sensor phenomena, technology, networks, and systems integration 2015 CY - San Diego, CA, USA DA - 08.03.2015 KW - Fibre-optic sensor KW - Standard KW - Temperature KW - Strain KW - Monitoring KW - Reliability KW - Application PY - 2015 DO - https://doi.org/10.1117/12.2185602 SN - 0277-786X VL - 9436 SP - 94360S-1 EP - 94360S-7 AN - OPUS4-33814 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Basedau, Frank A1 - Hofmann, Detlef A1 - Krebber, Katerina A1 - Jentsch, H. A1 - Senze, A. ED - Ilki, A. ED - Motavalli, M. ED - Inci, P. ED - Köhli, M. T1 - Online-detection of slipping soil areas by embedded fiber-optic sensing rods N2 - Movements in geological areas are often caused by shear zones deep in the underground or by hardly observable slipping zones. Detection of movements reaching critical values is of crucial importance to avoid losses and harms. Optical sensor fibers with gauge lengths of several meters or even distributed fiber-optic sensors with gauge lengths of hundreds of meters allow detecting deformation of such zones with quite good resolution. The paper presents a new technology of detecting deformations and movements in soil or rock massifs. The core part of the sensing system is a tiny pultruded rod with an outer diameter of 3 mm to 6 mm. It contains two fiber-optic sensor systems. One sensor system is used for permanent online measurement and provides integral strain information along the whole length of the rod; in case of critical deformations, it provides a warning signal. The second sensing system uses fiber-optic Bragg grating (FBG) strain sensors located close to the expected shear zone. This measurement system will be activated after the warning signal has been initiated by the integral strain measurement system. The FBG strain sensor system records then resulting deformations in detail. The sensing rod containing both sensor systems can be installed in a borehole to detect beginning soil movements automatically. The electronic equipment is powered by a solar panel; the amount of deformation in soil or rock formations can be estimated from the strain change measured in the sensor fibers. The effectiveness of this warning system will be shown using the example of a critically sliding slope in an open brown coal pit in Germany. T2 - SMAR 2015 - 3rd Conference on smart monitoring, assessment and rehabilitation of civil structures CY - Antalya, Turkey DA - 07.09.2015 KW - SHM KW - Standardization KW - Reliability KW - Fibre-optic sensor KW - Embedded sensor KW - Monitoring KW - Maintenance PY - 2015 SN - 978-3-905594-65-2 SP - Paper 222, 1 EP - 8 AN - OPUS4-34544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Cetinkaya, O. A1 - Schukar, Marcus A1 - Mergo, P. A1 - Krebber, Katerina T1 - Climatic stability of polymer optical fibers for sensing applications N2 - Systematic investigation of annealing behavior of drawn PMMA fibers was performed. Dynamics of annealing process were measured under different environmental conditions by fiber longitudinal shrinkage monitoring. Process was found to follow stretched exponential decay function indicating heterogeneous nature of underlying molecular dynamics. Consequences of fiber annealing for climatic stability of polymer optical fiber-based sensors are discussed, emphasizing importance of fiber controlled post-fabrication annealing. Dependence of induced fiber shrinkage on annealing time, temperature and fiber drawing conditions is investigated and interpreted. In addition, strong influence of humidity on annealing process was observed, which was not recognized in previous studies. This further highlights role of fiber post-fabrication thermal treatment with respect to intended operating conditions. T2 - POF 2015 - 24th International conference on plastic optical fibers CY - Nuremberg, Germany DA - 22.09.2015 KW - Polymer optical fibers KW - Polymethyl methacrylate KW - Climatic stability KW - Fiber annealing PY - 2015 SP - 209 EP - 212 AN - OPUS4-34422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohwetter, Philipp A1 - Eisermann, René A1 - Krebber, Katerina ED - Kalinowski, H.J. ED - Fabris, J.L. ED - Bock, W.J. T1 - Distributed acoustic sensing: Towards partial discharge monitoring N2 - We report on the successful application of distributed acoustic sensing (DAS) to the detection of partial discharge (PD). A detection limit of about 1 nC discharge magnitude was achieved for PD in a real-scale model of a high voltage termination. Dedicated ultrasonic fibre-optic transducers were interrogated using coherent optical time-domain Rayleigh backscatter reflectometry (C-OTDR). Random quadrature demodulation was employed for retrieving relevant acoustic information from the raw C-OTDR backscatter traces. To our knowledge, our results are a first-time demonstration that quasi-distributed fibre-optic acoustic sensing is a candidate technology for the acoustic partial discharge monitoring of power cable joints and terminations. T2 - OFS2015 - 24rd International conference on optical fibre sensors CY - Curitiba, Brazil DA - 28.09.2015 KW - Distributed acoustic sensing KW - Coherent Rayleigh OTDR KW - Partial discharge KW - Acoustic emission KW - Silicone elastomer KW - Stress cone KW - High voltage cable accessories PY - 2015 SN - 9781628418392 DO - https://doi.org/10.1117/12.2194850 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 2015/9634 SP - 96341C-1 EP - 96341C-4 PB - SPIE CY - Bellingham, WA, USA AN - OPUS4-34407 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Liehr, Sascha A1 - Krebber, Katerina A1 - Steffen, Milan A1 - Wosniok, Aleksander T1 - Fördermaßnahme KMU-innovativ: Informations- und Kommunikationstechnologie (IKT), EMS-261-003 (Digital OFDR - Entwicklung der digitalen Frequenzbereichsanalyse zur verteilten Rückstreumessung in optischen Fasern-Teilvorhaben: Sensorverfahren und Systembetrachtung / Schlussbericht zum Teilvorhaben KW - Digital OFDR KW - Verteilte Rückstreumessung KW - Frequenzbereichsanalyse PY - 2015 IS - BAM Vh 8158 SP - 1 EP - 45 CY - Berlin AN - OPUS4-34170 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed Brillouin fiber optic sensor system for long-term structural health monitoring N2 - We report on the development of a distributed fiber optical sensor system for structural health monitoring of largc-scale geotechnical and civil infrastructures. The system is based on Brillouin frequency domain analysis (BOFDA) for distributed measurement of strain and temperature along Standard silica optical fibers used as sensors. By additional incorporation of the fiber optic sensors in geosynthetics, two-dimensional sensors can be realized. Such smart geosynthetics can be used for reinforeerneut 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. T2 - 16th International conference 'Technical dam control' CY - Wierchomla Mala, Poland DA - 29.09.2015 KW - Distributed fiber optical sensor KW - Brillouin frequency domain analysis KW - Smart geosynthetics KW - Structural health monitoring PY - 2015 SN - 978-83-64979-09-5 SP - 271 EP - 278 AN - OPUS4-34728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreier, Andy A1 - Jeschke, T. A1 - Petermann, K. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Analytical model for mode-based insertion loss in ball-lensed coupling of graded-index silica and polymer fibres N2 - Analytical model for ball-lensed couplers to calculate the insertion loss for each optical mode. The basis for the calculation are commercial perfluorinated polymer optical (PFGI-POFs) and silica based fibres (SOFs). The modal power distribution for given misalignments are presented as well as the reflection-based losses at all optical interfaces. Additionally, the ball-lensed interconnection between PFGI-POF and SOF was theoretically demonstrated. T2 - POF 2017: 26th International Conference on Plastic Optical Fibres CY - Aveiro, Portugal DA - 13.09.2017 KW - Polymer optical fibre KW - Optical connector PY - 2017 VL - 2017 SP - 1 EP - 4 AN - OPUS4-41979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henschel, H. A1 - Hoeffgen, S.K. A1 - Krebber, Katerina A1 - Kuhnhenn, J. A1 - Weinand, U. T1 - Influence of Fiber Composition and Grating Fabrication on the Radiation Sensitivity of Fiber Bragg Gratings N2 - The radiation-induced Bragg wavelength shift (BWS) was measured with type I gratings made of 12 fibers with very different composition, i.e., of fibers with an extremely different radiation-induced attenuation. With two of the fibers fabrication parameters like laser intensity, hydrogen loading, and annealing conditions after grating inscription were varied. With another fiber type I and type II gratings were made by a completely different process. With gratings made under identical conditions of the 12 fibers the radiation-induced BWS only varied by about a factor of three. Varying the fabrication parameters led to BWS differences up to nearly a factor of ten. KW - Fiber Bragg gratings KW - Gamma radiation KW - Optical fiber sensor KW - Radiation effects PY - 2008 DO - https://doi.org/10.1109/TNS.2008.2001039 SN - 0018-9499 SN - 1558-1578 VL - 55 IS - 4 SP - 2235 EP - 2242 PB - Institute of Electrical and Electronics Engineers (IEEE) CY - New York, NY, USA AN - OPUS4-18570 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Glötzl, R. A1 - Schneider-Glötzl, J. A1 - Gabino, L. A1 - Krywult, L. ED - Bernadette Havranek, ED - Masoud Motavalli, ED - Urs Meier, T1 - Distributed polymer optical fiber sensors in geotextiles for monitoring of earthwork structures T2 - 4th International conference on structural health monitoring of intelligent infrastructure CY - Zurich, Switzerland DA - 2009-07-22 KW - Distributed sensor KW - Optical fiber sensor KW - Geotextile KW - Technical textile KW - POF sensor KW - Structural health monitoring KW - SHM KW - OTDR KW - Fiber optic sensors KW - Polymer optical fibers (POF) KW - Strain sensor PY - 2009 SN - 978-3-905594-52-2 IS - Paper 520 SP - 1 EP - 7(?) CY - Zurich, Switzerland AN - OPUS4-19787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Münich, J.C. A1 - Stempniewski, L. A1 - Metschies, H. ED - Bernadette Havranek, ED - Masoud Motavalli, ED - Urs Meier, T1 - Distributed polymer optical fiber sensors integrated in technical textiles for monitoring of masonry structures T2 - 4th International conference on structural health monitoring of intelligent infrastructure CY - Zurich, Switzerland DA - 2009-07-22 KW - Structural health monitoring KW - Fiber optic sensors KW - OTDR KW - Polymer optical fibers (POF) KW - POF sensors KW - Distributed sensor KW - Strain sensor KW - Technical textiles KW - Masonry PY - 2009 SN - 978-3-905594-52-2 IS - Paper 521 SP - 1 EP - 7(?) CY - Zurich, Switzerland AN - OPUS4-19788 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Liehr, Sascha A1 - Lenke, Peter A1 - Wendt, Mario T1 - Distributed POF sensors for structural health monitoring - First practical applications and field tests results N2 - Distributed POF sensors based on OTDR have been developed for SHM purposes of geotechnical and masonry structures. The first field tests conducted at a creeping slope and a brick building have proved the functionality of the sensors. T2 - POF 2009 - 18th International conference on plastic optical fibers CY - Sydney, Australia DA - 2009-09-07 PY - 2009 IS - Session 1 (S1_25) SP - 1 EP - 6 CY - Sydney, Australia AN - OPUS4-19914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Marcus A1 - Grzemba, Birthe A1 - Krebber, Katerina A1 - Luber, M. T1 - Integration technology of POF sensors into composites for structural health monitoring N2 - We have investigated the application technology of polymer optical fibers (POF) as sensors integrated into respectively applied onto composites for structural health monitoring by using different manufacturing methods and several types of POF. T2 - POF 2009 - 18th International conference on plastic optical fibers CY - Sydney, Australia DA - 2009-09-07 KW - Optische Polymerfasern (POF) KW - Fasersensorik KW - Structural Health Monitoring KW - Faserverbundwerkstoffe KW - OTDR KW - Faser-Integration PY - 2009 IS - Session 1 (S1_25) SP - 1 EP - 4 CY - Sydney, Australia AN - OPUS4-19915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina ED - Fu-Kuo Chang, T1 - POF sensors integrated in technical textiles for monitoring of earthwork structures and masonry T2 - Structural health monitoring 2009 - 7th International workshop on structural health monitoring CY - Stanford, CA, USA DA - 2009-09-09 KW - Distributed strain sensor KW - Optical fiber sensor KW - Geotextile KW - Technical textiles KW - POF sensor KW - Structural health monitoring KW - SHM KW - OTDR PY - 2009 SN - 978-1-60595-007-5 VL - 2 SP - 1739 EP - 1746 PB - DEStech Publications, Inc. AN - OPUS4-19960 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 -