TY - CHAP A1 - Rostan, Katharina A1 - Kruglov, Roman A1 - Engelbrecht, Rainer T1 - 2x2 Factorial Calibration of FBG Sensors for Simultaneous Measurement of Temperature and Humidity in PEM Fuel Cells T2 - Sensor and Measurement Science International Conference 2023 N2 - Fiber Bragg grating (FBG) sensor technology is expected to make an important contribution to extending the lifetime of polymer electrolyte membrane (PEM) fuel cells. It allows accurate measurements of in-situ operating temperature and humidity, which is essential for an accurate control of both. For these applications an accurate and reliable calibration is crucial. This paper demonstrates the successful use of a 2x2 factorial calibration method for calibration of two standard FBGs for application in a PEM fuel cell. The calibrated low-cost FBG sensor allows temperature and humidity measurements with a RMS error (RMSE) of 0.45°C and 4.8 %RH, respectively. KW - Fiber Bragg grating KW - Temperature sensing KW - Humidity sensing KW - PEM fuel cell Y1 - 2023 SN - 978-3-9819376-8-8 U6 - https://doi.org/10.5162/SMSI2023/P56 VL - 2023 SP - 388 EP - 389 PB - AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf, Germany ER - TY - CHAP A1 - Dengler, Simon Andreas A1 - Luber, Michael A1 - Neff, Léon A1 - Hangen, Hartmut A1 - Schmauss, Bernhard A1 - Ziemann, Olaf A1 - Engelbrecht, Rainer T1 - OTDR Strain and Force Sensing by POF on Geotextiles in a Geotechnical Application Test T2 - 28th International Conference on Optical Fiber Sensors N2 - With polymer optical fibers (POF) attached to geotextiles, optical time domain reflectometry (OTDR) can be used to measure strain of the geotextile spatially resolved in soil. We test the technique in a geotechnical application test and thus demonstrate the functionality of the sensor for field use. Y1 - 2023 SN - 978-1-957171-30-2 U6 - https://doi.org/10.1364/OFS.2023.W4.91 PB - Optica Publishing Group CY - Washington, D.C. ER - TY - GEN A1 - Dengler, Simon Andreas A1 - Käfferlein, Tilmann A1 - Engelbrecht, Rainer A1 - Schmauss, Bernhard A1 - Ziemann, Olaf T1 - Dependence of POF End Surface Reflectivity on Surface Roughness T2 - Proceedings POF2023 KW - Fiber optics Y1 - 2023 ER - TY - JOUR A1 - Hager, Simon A1 - Oesinghaus, Helge A1 - Bachmann, Alexander A1 - Meinardus, Martin A1 - Hofmann, Thomas A1 - Engelbrecht, Rainer A1 - Glas, Karl T1 - CaCO₃ deposits in reverse osmosis Part III – Incipient Scaling detection via polymer optical fibre sensors. Comparison to hydrochemical prediction and image analytical methods JF - Brewing Science KW - Fiber optics KW - Reverse osmosis KW - Sensor Y1 - 2023 U6 - https://doi.org/10.23763/brsc23-03hager VL - 76 IS - 3/4 ER - TY - JOUR A1 - Weiland, Josef A1 - Kunze, Billy A1 - Luber, Michael A1 - Krüger, Naomi A1 - Schiebahn, Alexander A1 - Engelbrecht, Rainer A1 - Reisgen, Uwe T1 - Structural Health Monitoring of Adhesively Bonded Pipe-to-Socket Joints by Integration of Polymer Optical Fibers and Their Load-Dependent Transmission Properties JF - Sensors N2 - Adhesively bonded pipe-to-socket joints are used in numerous industrial applications. One example is in the transport of media, e.g., in the gas industry or in structural joints for such sectors as construction, wind energy, and the vehicle industry. To monitor such load-transmitting bonded joints, this study investigates a method based on the integration of polymer optical fibers into the adhesive layer. Previous methods for monitoring the condition of pipes, such as acoustic or ultrasonic methods or the use of glass fiber optic-based sensors (FBG or OTDR), are very complex in methodology and require cost-intensive (opto-) electronic devices to generate and evaluate the sensor signals; they are therefore unsuitable for large-scale use. The method investigated in this paper is based on the measurement of integral optical transmission with a simple photodiode under increasing mechanical stress. When tried at coupon level (single-lap joint), the light coupling was varied to obtain a significant load-dependent sensor signal. Based on an angle-selective coupling of 30° to the fiber axis, a drop of 4% of the optically transmitted light power by a load of 8 N/mm2 can be detected for the adhesively bonded pipe-to-socket joint with the structural adhesive Scotch Weld DP810 (2C acrylate). KW - Fiber optics KW - Adhesive bonds KW - Sensors Y1 - 2023 U6 - https://doi.org/10.3390/s23104748 SN - 1424-8220 VL - 23 IS - 10 PB - MDPI AG ER - TY - JOUR A1 - Weiland, Josef A1 - Kunze, Billy A1 - Luber, Michael A1 - Krüger, Naomi A1 - Schiebahn, Alexander A1 - Engelbrecht, Rainer A1 - Reisgen, Uwe T1 - Structural Health Monitoring of Adhesively Bonded Pipe-to-Socket Joints by Integration of Polymer Optical Fibers and Their Load-Dependent Transmission Properties JF - Sensors N2 - Adhesively bonded pipe-to-socket joints are used in numerous industrial applications. One example is in the transport of media, e.g., in the gas industry or in structural joints for such sectors as construction, wind energy, and the vehicle industry. To monitor such load-transmitting bonded joints, this study investigates a method based on the integration of polymer optical fibers into the adhesive layer. Previous methods for monitoring the condition of pipes, such as acoustic or ultrasonic methods or the use of glass fiber optic-based sensors (FBG or OTDR), are very complex in methodology and require cost-intensive (opto-) electronic devices to generate and evaluate the sensor signals; they are therefore unsuitable for large-scale use. The method investigated in this paper is based on the measurement of integral optical transmission with a simple photodiode under increasing mechanical stress. When tried at coupon level (single-lap joint), the light coupling was varied to obtain a significant load-dependent sensor signal. Based on an angle-selective coupling of 30° to the fiber axis, a drop of 4% of the optically transmitted light power by a load of 8 N/mm2 can be detected for the adhesively bonded pipe-to-socket joint with the structural adhesive Scotch Weld DP810 (2C acrylate). KW - Fiber optics KW - Sensors KW - Adhesive bonding Y1 - 2023 U6 - https://doi.org/10.3390/s23104748 SN - 1424-8220 VL - 23 IS - 10 PB - MDPI AG ER - TY - JOUR A1 - Weiland, Josef A1 - Schiebahn, Alexander A1 - Reisgen, Uwe A1 - Luber, Michael A1 - Ziemann, Olaf A1 - Engelbrecht, Rainer T1 - Zustandsüberwachung struktureller Klebungen unter Scherbeanspruchung durch Integration einer optischen Polymerfaser JF - Schweißen und Schneiden N2 - Das im hier vorgestellten Forschungsrojekt KlebPOF untersuchte Sensorkonzept der Zustandsüberwachung von Klebungen basiert auf der Integration eines Kunststoff-Lichtwellenleiters (polymere optische Faser, POF) in die Klebung. Die ähnlichen mechanischen Eigenschaften von POF und Klebstoff, beides Kunststoffe, haben zur Folge, dass Beanspruchungen des Klebstoffs auf die POF übertragen werden. Die Auswirkungen einer Belastung auf die optischen Eigenschaften des Lichtwellenleiters werden in Bezug auf die transmittierte Lichtleistung sowie auf den Einfluss der Winkelverteilung der aus der Faser austretenden Lichtstrahlen im Fernfeld untersucht und für den Einsatz zur Zustandsüberwachung von Klebverbindungen interpretiert. Die Ergebnisse an Couponproben zeigen, dass sich die Methode insbesondere für semi-strukturelle Klebstoffe, wie zum Beispiel 2K-Polyurethane oder 2K-Methylmethacrylate und eine Beanspruchung der Klebung auf Scherung gut eignet. In den Untersuchungen an dem Funktionsmuster, einer Rohr-Muffe-Klebung, waren sehr deutliche Änderungen im Sensorsignal frühzeitig vor Versagen detektierbar. Diese Änderung konnte mit kostengünstigen opto-elektronischen Komponenten detektiert werden. Damit eignet sich die Methode für eine integrale Zustandsüberwachung der gesamten Klebung ohne Ortsauflösung, um einen kostengünstigen Sensor für den Feldeinsatz zu ermöglichen. KW - Kleben KW - Werkstoffragen Y1 - 2023 IS - 8 PB - DSV Media CY - Düsseldorf ER - TY - CHAP A1 - Kruglov, Roman A1 - Engelbrecht, Rainer T1 - Rapid and High-Resolution Tunable Diode Laser Spectroscopy within 10 µs for Combustion Gas Analysis T2 - Optica Sensing Congress 2023 (AIS, FTS, HISE, Sensors, ES) N2 - We report on a rapid high-resolution absorption spectroscopy with a VCSEL reaching a peak tuning speed of 2.1 nm/µs (8.8 cm-1/µs) near 1.5 µm. An overall tuning range of up to 12 nm can be achieved within a 12 µs injection current pulse. KW - Laser spectroscopy KW - Semiconductor lasers Y1 - 2023 SN - 978-195717124-1 U6 - https://doi.org/10.1364/sensors.2023.stu2d.3 PB - Optica Publishing Group CY - Washington, D.C. ER - TY - GEN A1 - Engelbrecht, Rainer A1 - Dengler, Simon Andreas A1 - Luber, Michael A1 - Vinogradov, Juri A1 - Ziemann, Olaf T1 - Condition Monitoring with POF: Recent Progress on Geotextiles and Wind Turbines T2 - Proceedings POF2023 Y1 - 2023 ER - TY - CHAP A1 - Rostan, Katharina A1 - Kruglov, Roman A1 - Seiß, Volker A1 - Thiel, Susanne A1 - Eichelbaum, Maik A1 - Engelbrecht, Rainer T1 - In-situ Temperature and Humidity Measurement in PEM Fuel Cells with Off-the-shelf FBG T2 - 28th International Conference on Optical Fiber Sensors N2 - We propose a cost efficient fiber Bragg grating (FBG) sensor for measuring temperature and humidity in polymer electrolyte membrane fuel cells (PEMFC). The multiparameter sensor works with two conventional FBG and achieves an RMSE better than 0.45°C and 4.8 %RH. KW - Proton exchange membrane fuel cells KW - Temperature and humidity KW - Fiber Bragg grating Y1 - 2023 SN - 978-1-957171-30-2 U6 - https://doi.org/10.1364/OFS.2023.Tu3.36 VL - 2023 PB - Optica Publishing Group CY - Washington, D.C. ER -