TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Characterizing vibration response of fiber cables for distributed acoustic sensing N2 - The vibration responses of two fiber cables are characterized up to 16 kHz and compared with a standard tight-buffered 900 um fiber. The response of the cables is suppressed due to the cable protection. T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Distributed fiber sensing KW - Acoustic sensing KW - Response characterization PY - 2022 AN - OPUS4-56099 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Weege, S. A1 - Roske, T. A1 - Krebber, Katerina T1 - Leakage detection at a borehole simulator using distributed acoustic sensing N2 - A distributed acoustic sensing system is used to detect the leakage in a borehole simulator by measuring the leakage induced vibration. The leakage location can be clearly determined by frequency spectrum analysis. T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Leakage detection KW - Structural health monitoring KW - Distributed fiber sensing KW - Distributed acoustic sensing PY - 2022 SP - 1 EP - 4 PB - Optica CY - Washington D.C., USA AN - OPUS4-56097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Characterizing vibration response of fiber cables for distributed acoustic sensing N2 - The vibration responses of two fiber cables are characterized up to 16 kHz and compared with a standard tight-buffered 900 um fiber. The response of the cables is suppressed due to the cable protection T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Response characterization KW - Distributed fiber sensing KW - Acoustic sensing PY - 2022 SP - 1 EP - 4 PB - Optica CY - Washington D.C., USA AN - OPUS4-56096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Weege, S. A1 - Roske, T. A1 - Krebber, Katerina T1 - Leakage detection at a borehole simulator using distributed acoustic sensing N2 - A distributed acoustic sensing system is used to detect the leakage in a borehole simulator by measuring the leakage induced vibration. The leakage location can be clearly determined by frequency spectrum analysis. T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Structural health monitoring KW - Distributed fiber sensing KW - Distributed acoustic sensing KW - Leakage detection PY - 2022 AN - OPUS4-56098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Popiela, Bartosz A1 - Günzel, Stephan A1 - Schukar, Marcus A1 - Mair, Georg W. A1 - Krebber, Katerina A1 - Seidlitz, Holger T1 - Impact of internal pressure control during manufacturing on residual stresses and safety performance of type 4 pressure vessels N2 - Composite pressure vessels are commonly manufactured using the wet filament winding process, where various process parameters can influence the performance of the finished component. In this study two designs of wet filament wound 6.8-liter type 4 composite pressure vessels were manufactured. Both differ only by the internal pressure used during the filament winding, which primarily influences the residual stress state in the composite structure. An extensive experimental study was carried out, including 10 slow burst tests and strain measurements with fiber optic sensors. Significant differences can be observed in the performance of the two designs even though the used stacking sequence, materials and other manufacturing parameters are the same for both designs. A discussion of the differences in the behavior of both cylinder types is provided, including the strain distribution in slow burst tests and failure mechanism. KW - Residual stresses KW - Slow burst tests KW - Filament winding KW - Type 4 composite pressure vessels KW - Hydrogen PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626663 DO - https://doi.org/10.1016/j.jcomc.2025.100581 SN - 2666-6820 VL - 17 SP - 1 EP - 9 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-62666 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Glötzl, R. ED - Boller, C. T1 - Development of a PMMA-POF based fiber optic inclinometer with smart transport and installation characteristics N2 - We present the state of our work concerning the development of a fiber optic inclinometer based on PMMA POF which provides distributed sensitivity regarding level, direction and location of deformation within critical ground structures. According to the demand for simple less expensive Installation and Operation of reliable sensor Systems a sensor concept has been developed and to our knowledge the first results of a PMMA POF based inclinometer prototype are presented in the following chapters. T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 03.07.2012 PY - 2012 SN - 978-3-940283-41-2 IS - Chapt. Optical Sensors SP - 411 EP - 416 CY - Berlin AN - OPUS4-26193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wendt, Mario A1 - Krebber, Katerina T1 - Using optical POF switches for distributed fiber optical strain measurements N2 - During recent research projects FOS sensor Systems based on PMMA (see fig.l) and perfluorined POF have been developed in order to observe critical earth structures [1,2], The sensor Systems enables real distributed Observation of objects due to the use of OTDR technique, whereas an increased Rayleigh backscatter level is observed at the strained fiber section. Fürther both used POF types are very robust which makes the sensor System suitable for harsh environment condilions and secure continuous measurements even within strong deformed structures. These characteristics offer opportunities to complement the arsenal of established electric based sensor Systems. However, due to high cost of OTDR devices the developed sensor System is not ready for the market yet. To make an improvement here the feasibility of optical switches have been investigated in order to use multiple single sensor lines connected to one OTDR device. Despite to the fact that optical switches are established in the field of telecommunication the use for distributed optical measurements is to our knowledge not investigated yet. One question which has to be answered is if strong reflections which occur at fiber couplings disable the Signals of the single sensor lines. A further interest is to secure that the known sensing characteristics of the single System is still provided via optical switch. For this purpose two optical switches each adapted to PMMA and perfluorined characteristics respectively have been tested. Laboratory tests have been conducted, whereas two OTDR units for PMMA and perfluorined POF were available. Finally the switches have been tested during field tests. T2 - POF 2012 - 21st International conference on plastic optical fibers CY - Atlanta, Georgia, USA DA - 10.09.2012 KW - Distributed strain sensors KW - Optical switch KW - OTDR PY - 2012 SP - 133 EP - 136 AN - OPUS4-26743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Popiela, Bartosz A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Günzel, Stephan A1 - Mair, Georg W. A1 - Krebber, Katerina A1 - Seidlitz, Holger T1 - Embedding of Fiber Optic Sensors Under Industrial Conditions and Distributed Strain Sensing in Type 4 Composite Pressure Vessels N2 - The number of in-operation composite pressure vessels is increasing, partly due to their attractiveness for on-board compressed gas storage and transport applications. A possible way to maintain the highest safety levels is through the structural health monitoring of the composite cylinders. Here, the use of fiber optic sensors appears to be a promising approach. However, the integration of the optical fibers into the composite structure of a pressure vessel has been shown to be challenging. In this study, insights on the embedding of optical fibers in the composite structure under industrial conditions are provided. A protection concept for the ingress and egress of the optical fibers is presented. Finally, the results from destructive slow burst tests are evaluated, showing no clear trend in the impact of the embedded optical fibers on the performance of composite pressure vessels. T2 - 24th International Conference on Composite Materials CY - Baltimore, Maryland, USA DA - 04.08.2025 KW - Composite KW - Pressure vessel KW - Filament winding KW - Fiber optic sensors PY - 2025 SP - 3710 EP - 3717 AN - OPUS4-63886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Witt, Jens A1 - Narbonneau, F. A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - De Jonckheere, J. A1 - Jeanne, M. A1 - Kinet, D. A1 - Paquet, B. A1 - Depré, A. A1 - D´Angelo, L.T. A1 - Thiel, T. A1 - Logier, R. T1 - Medical textiles with embedded fiber optic sensors for monitoring of respiratory movement N2 - For patients under Magnetic Resonance Imaging (MRI) spontaneous respiration is constantly at risk of being impaired by anesthetic drugs or by upper airway obstruction. Therefore, continuous monitoring of the breathing activity is needed to assess adequate ventilation or to detect specific obstruction patterns. The paper describes three MRI compatible respiration sensors based on pure optical technologies developed within the EU FP6 project OFSETH. The sensors are based on fiber Bragg gratings, optical time-domain reflectometry and macrobending effects. The developed smart medical textiles can sense elongation up to 3% while maintaining the stretching properties of the textile substrates for patient's comfort. The OFSETH harness allows a continuous measurement of abdominal and thoracic respiration movement while all vitals organs are free for medical staff actions. The sensors were tested in MRI environment and on healthy adults. KW - Fiber optic sensor KW - Polymer optical fiber (POF) sensor KW - Respiratory sensor KW - Smart medical textile KW - MRI KW - Smart textile KW - Healthcare monitoring KW - Optical sensor KW - FBG PY - 2012 DO - https://doi.org/10.1109/JSEN.2011.2158416 SN - 1530-437X SN - 1558-1748 VL - 12 IS - 1 SP - 246 EP - 254 CY - New York, NY, USA AN - OPUS4-25649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witt, Jens A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Demuth, J. A1 - Pazoutová, H. A1 - Sasek, L. A1 - Santostefano, N. A1 - Fiore, L. A1 - Uotila, J. A1 - Pietrowski, P. T1 - POF sensors for personal protective equipment (PPE) N2 - This paper reports about the EU project i-Protect in which fibre optic sensors for measuring heart rate, respiratory rate and skin temperature are being developed. The sensors and monitoring units are integrated into underwear and are communicating wireless via body area network and communication unit with the rescue command centre. All sensors can be removed from the underwear to allow washing the textile. T2 - POF 2012 - 21st International conference on plastic optical fibers CY - Atlanta, Georgia, USA DA - 10.09.2012 KW - Physiological sensor KW - Heart rate KW - Respiratory rate KW - Photoplethysmography KW - Technical textile PY - 2012 SP - 333 EP - 338 AN - OPUS4-27397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hussels, Maria-Teresa A1 - Chruscicki, Sebastian A1 - Habib, Abdel Karim A1 - Krebber, Katerina T1 - Distributed acoustic fibre-optic sensors for condition monitoring of pipelines N2 - Industrial piping systems are particularly relevant to public safety and the continuous availability of infrastructure. However, condition monitoring systems based on many discrete sensors are generally not well-suited for widespread piping systems due to considerable installation effort, while use of distributed fibre-optic sensors would reduce this effort to a minimum. Specifically distributed acoustic sensing (DAS) is employed for detection of third-party threats and leaks in oil and gas pipelines in recent years and can in principle also be applied to industrial plants. Further possible detection routes amenable by DAS that could identify damage prior to emission of medium are subject of a current project at BAM, which aims at qualifying distributed fibre optic methods such as DAS as a means for spatially continuous monitoring of industrial piping systems. Here, first tests on a short pipe are presented, where optical fibres were applied directly to the surface. An artificial signal was used to define suitable parameters of the measurement system and compare different ways of applying the sensor. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, Ireland DA - 31.05.2016 KW - fibre-optic condition monitoring KW - distributed acoustic sensing (DAS) KW - pipeline monitoring KW - sensor application PY - 2016 SN - 978-1-5106-0219-9 DO - https://doi.org/10.1117/12.2236809 SN - 0277-786X VL - Vol. 9916 SP - Article Number: 99162Y PB - SPIE CY - Bellingham, Washington USA AN - OPUS4-37234 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stajanca, Pavol A1 - Cetinkaya, O. A1 - Schukar, Marcus A1 - Mergo, P. A1 - Webb, D. J. A1 - Krebber, Katerina T1 - Molecular alignment relaxation in polymer optical fibers for sensing applications N2 - A systematic study of annealing behavior of drawn PMMA fibers was performed. Annealing Dynamics were investigated under different environmental conditions by fiber longitudinal shrinkage monitoring. The shrinkage process was found to follow a stretched exponential decay function revealing the heterogeneous nature of the underlying molecular dynamics. The complex dependence of the fiber shrinkage on initial degree of molecular alignment in the fiber, annealing time and temperature was investigated and interpreted. Moreover, humidity was shown to have a profound effect on the annealing process, which was not recognized previously. Annealing was also shown to have considerable effect on the fiber mechanical properties associated with the relaxation of molecular alignment in the fiber. The consequences of fiber annealing for the climatic stability of certain polymer optical fiber-based sensors are discussed, emphasizing the importance of fiber controlled pre-annealing with respect to the foreseeable operating conditions. KW - Polymer optical fibers KW - Optical fiber sensor climatic stability KW - Thermal annealing KW - Molecular alignment relaxation KW - Humidity induced annealing PY - 2016 DO - https://doi.org/10.1016/j.yofte.2015.12.006 SN - 1068-5200 VL - 28 SP - 11 EP - 17 PB - Academic Press CY - Orlando AN - OPUS4-35288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Sporea, D. A1 - Mihai, L. A1 - Negut, D. A1 - Schukar, Marcus A1 - Krebber, Katerina ED - Bunge, C.-A. ED - Kruglov, R. T1 - Gamma radiation induced effects in perfluorinated polymer optical fibers for sensing applications N2 - Radiation induced attenuation in perfluorinated polymer optical fiber was investigated as a potential mean for online. in situ gamma radiation monitoring. Spectral dependence of radiation induced attenuation was measured in the visible and near infrared range. Attenuation spectrum exhibits sharp increase both towards the ultraviolet and infrared side of the spectrum with 3 distinct peaks around 1400 nm. The fiber sensitivity to gamma radiation was further evaluated at two commonly used IR wavelengths (1310nm and l550nm} by pre- and post-irradiation optical time-domain reflectometry measurements. The examined fiber is sensitive up to lOO kGy of total absorbed dose with only minor saturation towards the large dose values. The influence of gamma radiation on the fiber mechanical properties was studied as well. Up to the maximal dose of 100 kGy, no significant deterioration of fiber strength and elasticity was observed. T2 - 3rd International POF Modelling Workshop CY - Nuremberg, Germany DA - 21.09.2015 KW - Perfluorinated POF KW - Gamma radiation KW - Radiation induced losses KW - Radiation dosimetry PY - 2015 SN - 978-3739214993 SP - 95 EP - 103 PB - Books on Demand GmbH CY - Norderstedt AN - OPUS4-35287 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -