TY - CONF A1 - Bartholmai, Matthias T1 - Early damage detection of structural defects using guided waves T2 - 6th European Workshop on Structural Health Monitoring - Structural Health Monitoring 2012 CY - Dresden, Germany DA - 2012-07-03 PY - 2012 AN - OPUS4-26800 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias T1 - Multifunctional Sensor for Monitoring of CO2 Underground Storage by Comprehensive and Spatially Resolved Measuring of Gas Concentrations, Temperature, and Structural Changes T2 - Greenhouse Gas Control Technologies (GHGT-11) Conference CY - Kyoto, Japan DA - 2012-11-18 PY - 2012 AN - OPUS4-26885 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias T1 - Chances and limitations of RFID sensor systems – practical experiences from research projects with different application scenarios N2 - The combination of Radio-frequency identification (RFID) and low energy sensors offers promising chances to implement cost effective, easy to apply, and easy to handle sensor systems for a variety of applications. The RFID technology is already well established in logistics. Enhanced processing and interface capabilities enable the integration of various sensors for control, diagnostics, and monitoring tasks. In the scope of research projects carried out at the Federal Institute for Materials Research and Testing (BAM), RFID sensor systems were developed and validated with regard to two different application scenarios: the Identification and diagnosis of concrete components for road bridges and the monitoring of dangerous goods transportation. This contribution presents selected research results and reflects the practical experiences on future chances and limitations of RFID sensor systems. T2 - IDTechEx Show! Europe 2016 CY - Berlin, Germany DA - 27.04.2016 KW - RFID Sensors systems KW - Diagnosis of concrete components KW - Monitoring of dangerous goods PY - 2016 AN - OPUS4-36034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias 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 AN - OPUS4-38387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias T1 - Experimental Validation of the Cone-Shaped Remote Gas Sensor Model N2 - Remote gas sensors mounted on mobile robots enable the mapping of gas distributions in large or hardly accessible areas. A challenging task, however, is the generation of threedimensional distribution maps from these gas measurements. Suitable reconstruction algorithms can be adapted, for instance, from the field of computed tomography (CT), but both their performance and strategies for selecting optimal measuring poses must be evaluated. For this purpose simulations are used, since, in contrast to field tests, they allow repeatable conditions. Although several simulation tools exist, they lack realistic models of remote gas sensors. Recently, we introduced a model for a Tunable Diode Laser Absorption Spectroscopy (TDLAS) gas sensor taking into account the conical shape of its laser beam. However, the novel model has not yet been validated with experiments. In this paper, we compare our model with a real sensor device and show that the assumptions made hold. T2 - IEEE Sensors 2019 CY - Montreal, Canada DA - 27.10.2019 KW - Remote gas sensor model KW - TDLAS KW - Gas dispersion simulation PY - 2019 AN - OPUS4-49549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartelmeß, Jürgen A1 - Gawlitza, Kornelia A1 - Bartholmai, Matthias A1 - Rurack, Knut T1 - Developments towards the fluorescence based sensing of hazardous gases N2 - Fluorescence based sensing is a versatile approach for the trace analysis outside of the laboratory, requiring suitable sensor materials and their integration into sensing devices. The versatility of fluorophores as probes, especially in terms of the possibility to tailor their optical as well as their recognition properties by synthetic modifications in a wide range, renders them a superior active component for the preparation of optical sensor devices. Recent works at BAM in this field include, for example, the detection of nerve gas agents, illustrating impressively the aforementioned benefits of fluorophores in optical sensing applications. In the interdisciplinary approach presented here, we target hazardous gases such as ammonia, benzene, and hydrogen sulfide, next to others, which pose a major threat to human health and environmental safety and for which the availability of a sensitive and reliable detection method is highly desirable. The dyes presented follow a “turn-on” fluorescence schematic which allows for the selective and sensitive detection of the respective gaseous analyte. The immobilization of the probe in polymeric matrices is then the next step toward the fabrication of a prototype device for molecular sensing. T2 - Colloquium of Optical Spectrometry (COSP) 2017 CY - Berlin, Germany DA - 27.11.2017 KW - Gas sensing KW - Fluorescence KW - KonSens PY - 2017 AN - OPUS4-43209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -