TY - CONF A1 - Bartholmai, Matthias ED - Werner, Klaus-Dieter T1 - Temperature characteristics of a piezoresistive accelerometer for high impact shock application N2 - This study presents the characterization of a piezoresistive accelerometer damped with silicon oil for the application in drop tests carried out at BAM. Experiments were performed with the Hopkinson Bar method in close correlation to the real-world application conditions. The results point out certain limitations regarding the temperature influence and the frequency response. Additional experiments were performed with a gas damped type of piezoresistive accelerometer, which has superior specifications, particularly for low temperatures. The results allow for a comparison. T2 - Sensoren und Messsysteme CY - Nürnberg, Germany DA - 26.06.2018 KW - Piezoresistive accelerometer KW - High impact shock application KW - Drop test KW - Temperature characteristics KW - Hopkinson bar PY - 2018 SN - 978-3-8007-4683-5 SN - 0932-6022 SP - 465 EP - 467 PB - VDE Verlag GmbH CY - Berlin AN - OPUS4-45323 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Ebert, Sebastian A1 - Neumann, Patrick P. A1 - Noske, Reinhard A1 - Rehak, W. A1 - Lazik, D. T1 - Linear gas sensor for methane based on a selectively permeable membrane N2 - In preliminary work, gas sensors in linear form based on the measuring principle of gas selective permeability through a membrane were developed and introduced for the detection and quantification of gas concentrations. In this study, first experimental results are presented for adapting the technology for measuring methane (CH4). A material with suitable selective permeability was identified and utilized in a sensor setup containing the gas selective membrane and a reference membrane, both integrated in a measuring cell, to which a gas stream with defined CH4 concentrations was applied. The results prove the sensor's capability for measuring methane and indicate further application potential of the method, e.g., as a robust field monitoring technology, since CH4 is the major component of natural gas, town gas, and fracking gas. T2 - AMA Conferences 2015 with SENSOR and IRS2 CY - Nuremberg, Germany DA - 19.05.2015 KW - Selective permeability KW - Quantification of gas concentrations KW - Spatially distributed monitoring KW - Gas storage sites KW - Methane measuring PY - 2015 SN - 978-3-9813484-8-4 U6 - https://doi.org/10.5162/sensor2015/P8.1 SP - 833 EP - 835 AN - OPUS4-33263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Johann, Sergej A1 - Kammermeier, Michael A1 - Müller, Maximilian A1 - Strangfeld, Christoph T1 - RFID sensor systems embedded in concrete – systematical investigation of the transmission characteristics N2 - Long-term completely embedded sensor systems offer innovative possibilities for structural health monitoring of concrete structures. Measuring of relevant parameters, e.g., temperature, humidity, or indication of corrosion can be performed with low energy sensors. This allows to implement passive RFID sensor systems without cable connection and battery, which are power supplied exclusively by the electromagnetic field from the external reader device. To evaluate characteristics and conditions of this concept, a systematical investigation of the transmission characteristics with variation of relevant parameters, as communication frequency, installation depth, type of concrete, moisture content, etc. is currently carried out in an interdisciplinary research project at BAM. First results are presented in this paper. T2 - 8th European Workshop On Structural Health Monitoring CY - Bilbao, Spain DA - 05.07.2016 KW - Structural health monitoring KW - Embedded sensor KW - Energy harvesting KW - Wireless sensors KW - RFID sensors KW - Transmission characteristics PY - 2016 SP - 1 EP - 5 AN - OPUS4-37129 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Johann, Sergej A1 - Kammermeier, Michael A1 - Müller, Maximilian A1 - Strangfeld, Christoph T1 - Transmission characteristics of RFID sensor systems embedded in concrete N2 - Completely embedded sensor systems for long-term operation offer innovative possibilities for structural health monitoring of concrete structures. Measuring of relevant parameters, e.g., temperature, humidity, or indication of corrosion can be performed with low energy sensors. This allows to implement passive RFID sensor systems without cable connection and battery, which are power supplied exclusively by the electromagnetic field from the external reader device. To evaluate characteristics and conditions of this concept, a systematical investigation of the transmission characteristics with variation of relevant parameters, as communication frequency, installation depth, type of concrete, moisture content, etc. is currently carried out in an interdisciplinary research project at BAM. First results are presented in this paper. T2 - IEEE Sensors 2016 CY - Orlando, FL, USA DA - 30.10.2016 KW - Embedded sensors KW - Energy harvesting KW - Wireless sensors KW - RFID sensors KW - Transmission characteristics KW - Structural health monitoring PY - 2016 SN - 978-1-4799-8287-5 SN - 1930-0395 SP - 1541 EP - 1543 PB - IEEE AN - OPUS4-38388 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Johann, Sergej A1 - Strangfeld, Christoph ED - Chan, T. ED - Mahini, S, T1 - Embedded wireless sensor systems for long-term SHM and corrosion detection in concrete components N2 - State-of-the-art communication standards like RFID and Bluetooth Low Energy enable the development of sensor systems which can be completely embedded into concrete components for long-term SHM and early damage detection. Objective of the project KonSens which is carried out at BAM is the development, implementation, and validation of sensors for measuring of Parameters relevant for corrosion, like moisture, pH value, and electrical conductivity, inside steel reinforced concrete components. The primarily addressed application is detection and evaluation of corrosion processes in concrete bridges. In contrast to cable connected sensors, embedded wireless sensors avoid any pathways for intrusion of moisture and chemicals, e.g., chlorides which could trigger corrosion activity. To allow for long-term, ideally life-time operation, the once embedded sensor systems must work highly energy efficient. One option are passive RFID sensor systems, which work without battery. The energy is transmitted to the system through the electromagnetic field, even to operate sensors. A crucial parameter is the transmission depth in concrete. First experiments with RFID sensors working at frequencies of 13.56 MHz (HF) and 868 MHz (UHF) embedded in concrete specimen resulted positive for transmission depths of up to 13 cm, which is quite promising, considering that corrosion would appear first at the top level of rebars. A second generation of passive RFID sensor systems has been implemented with improved antenna design. Current experiments using these systems focus on the Transmission characteristics in terms of transmission depths and the impact of concrete moisture. Low-energy humidity sensors are used and analysed regarding their capability for measuring the material moisture. Additionally, a relation between transmitted power to the embedded sensor and the moisture content of the concrete specimen caused by energy absorption can be presumed and is under systematic investigation. T2 - International Conference on Structural Health Monitoring of Intelligent Infrastructure 2017 CY - Brisbane, Australia DA - 05.12.2017 KW - RFID sensors KW - Structural health monitoring KW - Sensors in concrete KW - Smart structures PY - 2017 SN - 978-1-925553-05-5 SP - 1 EP - 7 AN - OPUS4-43492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Köppe, Enrico ED - Urs Meier, ED - Bernadette Havranek, ED - Masoud Motavalli, T1 - Wireless sensor network for long-term structural health monitoring of buildings and infrastructures N2 - Damage commonly occurs in buildings when a component fails suddenly with a partial or total collapse as a consequence. This type of event leads to serious damage to property and if it is a bridge or a large hall, then people in particular are at risk. The often great age of bridges and the increasing volume of traffic (particularly heavy traffic) which they are expected to carry are in clear contradiction to each other. Thus the probability increases that the loadbearing capacity of a bridge decreases rapidly and often unnoticed with sometimes dire consequences. In order to prevent such accidents, the Federal Institute for Materials Research and Testing is currently developing a special radio-based, self-configuring measuring system in cooperation with the Berlin-based ScatterWeb Company. This measuring system consists of a number of identically designed sensor nodes which are self-sustaining, need no wiring, can act as both transmitters and receivers and are equipped with a special sensor technology making long-term monitoring of buildings or engineering facilities possible. The sensor unit uses strain gauges for stress analysis and contains interfaces for additional sensors. The system in particular applies to buildings and structures for transport and traffic and large-scale industrial facilities, where a subsequent wiring installation is difficult or impossible. T2 - 4th International conference on structural health monitoring of intelligent infrastructure CY - Zurich, Switzerland DA - 2009-07-22 KW - Funksensorik KW - Sensornetzwerk KW - Schadensfrüherkennung KW - Strukturüberwachung PY - 2009 IS - Paper 365 SP - 1 EP - 5 AN - OPUS4-19748 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Köppe, Enrico A1 - Neumann, Patrick P. T1 - Monitoring of hazardous scenarios using multi-sensor devices T2 - Sensordevices 2013 - The 4th International conference on sensor device technologies and applications CY - Barcelona, Spain DA - 2013-08-25 KW - Multi-sensor device KW - Hazardous scenarios KW - Data-fusion PY - 2013 SN - 978-1-61208-297-4 SP - 9 EP - 13 AN - OPUS4-29069 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Köppe, Enrico A1 - Prager, Jens ED - Boller, C. T1 - Early damage detection of structural defects using guided waves N2 - Limited access to the object of relevance is often an essential problem in testing routines, e.g. for non-destructive testing of industry facilities or components of means of transportation. The presented project is about the development of a non-destructive testing method for application over great distances (up to 100 m). The method is based on directed excitation and measuring of Lamb waves (guided waves). It enables an effective differentiation of structural and defective indications as well as a classification of different defect types. The advantage of guided waves is the ability of propagation over great distances. This offers innovative possibilities for the investigation of large or difficult to access constructions. The testing method can be helpful in a broad variety of applications. It is useable for the characterization of plane or cylindrical, thin-walled surfaces of metal or fiber laminated materials. Particularly the investigation of aircraft wings and other aerospace components as well as the investigation of pipelines are addressed fields of application. T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 03.07.2012 KW - Lamb-waves KW - Ultrasound KW - Non-destructive evaluation KW - Early-damage-detection KW - Structural health monitoring PY - 2012 SN - 978-3-940283-41-2 VL - 2 SP - 1471 EP - 1478 CY - Berlin AN - OPUS4-26240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Neumann, Patrick P. A1 - Kohlhoff, Harald A1 - Daum, Werner T1 - Multi-sensor systems for safety-related monitoring T2 - Sensor 2013 - 16th International conference on sensors and measurement technology CY - Nürnberg, Germany DA - 2013-05-14 KW - Multi-sensor system KW - Condition monitoring KW - Safety management KW - Hazardous scenarios KW - Data-fusion PY - 2013 SN - 978-3-9813484-3-9 U6 - https://doi.org/10.5162/sensor2013/B5.2 N1 - Serientitel: AMA Conferences – Series title: AMA Conferences SP - 268 EP - 272 AN - OPUS4-28518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Neumann, Patrick P. A1 - Werner, Klaus-Dieter A1 - Ebert, Sebastian A1 - Lazik, D. T1 - Linear sensor for areal subsurface gas monitoring - calibration routine and validation experiments N2 - Membrane based linear gas sensors and fiber optical sensors feature similar geometries and complement each other in quantities to be measured. To the author's best knowledge, it is the first time that these sensors are combined to a multifunctional sensor for distributed measuring of gas concentrations, temperature, and strain. Objective is a comprehensive monitoring of underground gas storage areas. In the presented project a 400 m² test site and a corresponding laboratory system were just built up to characterize, validate, and optimize the combined sensor. Application of the sensor lines in a grid structure should enable spatial resolution of the measurement data and early detection of relevant events, as gas leakage, temperature change, or mechanical impact. A Calibration routine was developed which can be applied subsequent to underground installation. First measurement results indicate the potential of the method, with regard to highly topical energy transport and storage issues. T2 - IEEE Sensors 2014 conference CY - Valencia, Spain DA - 02.11.2014 KW - Linear sensor KW - Distributed sensor KW - Monitoring of CO2 KW - Subsurface monitoring KW - Gas storage areas KW - Membrane-based gas sensing KW - Fibre optical sensing PY - 2014 SN - 978-1-4799-0161-6 U6 - https://doi.org/10.1109/ICSENS.2014.6985157 SP - 942 EP - 945 AN - OPUS4-32083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -