8.1 Sensorik, mess- und prüftechnische Verfahren
Filtern
Dokumenttyp
- Vortrag (118)
- Beitrag zu einem Tagungsband (56)
- Zeitschriftenartikel (43)
- Posterpräsentation (34)
- Sonstiges (5)
- Beitrag zu einem Sammelband (1)
- Video (1)
- Preprint (1)
- Forschungsdatensatz (1)
Sprache
- Englisch (198)
- Deutsch (60)
- Mehrsprachig (2)
Schlagworte
- QI-Digital (22)
- Hydrogen (15)
- H2Safety@BAM (13)
- Mobile Robot Olfaction (13)
- Digital Calibration Certificate (12)
- Calibration (11)
- Gas Tomography (11)
- Digital Metrology (10)
- Environmental monitoring (10)
- Gas source localization (10)
Organisationseinheit der BAM
- 8 Zerstörungsfreie Prüfung (260)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (260)
- 1 Analytische Chemie; Referenzmaterialien (37)
- 8.2 Zerstörungsfreie Prüfmethoden für das Bauwesen (21)
- 9 Komponentensicherheit (20)
- 3 Gefahrgutumschließungen; Energiespeicher (19)
- 2 Prozess- und Anlagensicherheit (17)
- 8.6 Faseroptische Sensorik (15)
- 1.5 Proteinanalytik (14)
- 8.4 Akustische und elektromagnetische Verfahren (14)
Paper des Monats
- ja (6)
Mikrolegierungselemente wie Niob (Nb) und Titan (Ti) spielen eine entscheidende Rolle bei der Einstellung der gewünschten mechanischen Eigenschaften vergüteter hochfester Feinkornbaustähle mit einer Nennstreckgrenze von ≥ 690 MPa. Aktuelle Spezifikationen der chemischen Zusammensetzung definieren für diese Elemente lediglich Obergrenzen und gewähren den Herstellern damit einen gewissen Spielraum. Bereits geringfügige Abweichungen in den Legierungskonzepten können jedoch die resultierenden mechanischen Eigenschaften erheblich beeinflussen. Infolgedessen wird die zuverlässige Vorhersage der Schweißeignung sowie der Integrität geschweißter Verbindungen aufgrund von Zusammensetzungsvariationen und den damit verbundenen mikrostrukturellen Veränderungen erschwert oder sogar unmöglich. Mögliche nachteilige Effekte umfassen eine Aufweichung der Wärmeeinflusszone (WEZ) oder umgekehrt lokale Aufhärtungsphänomene. Zur Bewältigung dieser Herausforderungen werden erstmals verschiedene Mikrolegierungsstrategien mit unterschiedlichen Ti- und Nb-Gehalten systematisch anhand speziell hergestellter, im Labor gegossener Legierungen untersucht. Jeder Legierungsansatz basiert auf dem häufig verwendeten Stahl S690QL, wobei eine konsistente chemische Zusammensetzung sowie identische Wärmebehandlungsparameter beibehalten werden.
Zur Bewertung der Schweißeignung wurden dreilagige Schweißverbindungen mittels Metall-Schutzgasschweißen durchgeführt und kritische mikrostrukturelle Bereiche – insbesondere solche innerhalb der Wärmeeinflusszone (WEZ) mit ausgeprägter Aufweichung oder Aufhärtung – identifiziert. Der Einfluss der aufgeweichten WEZ-Bereiche auf das Versagensverhalten wurde durch Querzugversuche untersucht. Zur In-situ-Analyse lokaler Dehnungsverteilungen in verschiedenen WEZ-Regionen wurde die digitale Bildkorrelation (DIC) eingesetzt. Darüber hinaus wurden Kerbschlagbiegeversuche (Charpy) an Grundwerkstoff, Schweißgut und WEZ durchgeführt, um die Kerbschlagzähigkeit zu bestimmen.
Controlling trace humidity is vital for both the fabrication and long-term stability of metal halide perovskite (MHP) solar cells. Relevant humidity levels are typically below 10 ppmV, especially in glovebox-based processing and in well-encapsulated devices. Even minute amounts during fabrication can influence crystallization, introducing defects and lowering efficiency. Over time, humidity accelerates degradation of the perovskite layer and internal interfaces, ultimately reducing operational lifetime. Probing these effects at low concentrations under operando conditions is therefore essential for advancing device performance and durability. In this work, we employed a high-precision transfer standard dew point hygrometer to investigate humidity levels between 5 and 35 ppmV in non-encapsulated MHP solar cells. To permit unobstructed water migration during operation, we fabricated interdigital back contact devices. Operando measurements revealed water transport through the perovskite layer and enabled quantification of outgassing. Under trace-humidified conditions, devices exhibited initial charge-carrier quenching, followed by gradual recovery. Notably, the photocurrent response to humidified nitrogen demonstrated that the MHP layer behaves fully reversibly within the explored timescale and across the investigated humidity levels and conditions. These findings establish a systematic operando framework for examining extrinsic stressors in perovskites and highlight opportunities for assessing passivation strategies.
Controlling trace humidity is vital for both the fabrication and long-term stability of metal halide perovskite (MHP) solar cells. Relevant humidity levels are typically below 10 ppmV, especially in glovebox-based processing and in well-encapsulated devices. Even minute amounts during fabrication can influence crystallization, introducing defects and lowering efficiency. Over time, humidity accelerates degradation of the perovskite layer and internal interfaces, ultimately reducing operational lifetime. Probing these effects at low concentrations under operando conditions is therefore essential for advancing device performance and durability. In this work, we employed a high-precision transfer standard dew point hygrometer to investigate humidity levels between 5 and 35 ppmV in non-encapsulated MHP solar cells. To permit unobstructed water migration during operation, we fabricated interdigital back contact devices. Operando measurements revealed water transport through the perovskite layer and enabled quantification of outgassing. Under trace-humidified conditions, devices exhibited initial charge-carrier quenching, followed by gradual recovery. Notably, the photocurrent response to humidified nitrogen demonstrated that the MHP layer behaves fully reversibly within the explored timescale and across the investigated humidity levels and conditions. These findings establish a systematic operando framework for examining extrinsic stressors in perovskites and highlight opportunities for assessing passivation strategies.
Methane emissions are a significant environmental and safety concern, yet many gas tomography systems intended to measure them require manual alignment, reliable high-bandwidth links, or fiducials. We present a lightweight, fully autonomous framework enabling line-of-sight inter-robot Tunable Diode Laser Absorption Spectroscopy (TDLAS) measurements without such constraints. A sensor robot equipped with a gimbal-mounted TDLAS unit tracks a reflector robot bearing an illuminated, color-controllable target. Coarse localization is achieved via RTK-GNSS, with vision-based fine tracking and passive time synchronization handled onboard. The system, based on off-the-shelf Pixhawk controllers and ArduPilot firmware, was validated in a 15m × 7m outdoor trial. Despite GNSS inaccuracies and deliberate occlusion by a methane-filled bag, the system retained lock, recovered from visual loss in under one second, and captured a 2800 ppm·m plume signature. These results demonstrate robust, scalable methane sensing for mobile gas tomography or standalone leak detection. Core components are released open-source to support future deployment.
Methane emissions are a significant environmental and safety concern, yet many gas tomography systems intended to measure them require manual alignment, reliable high-bandwidth links, or fiducials. We present a lightweight, fully autonomous framework enabling line-of-sight inter-robot Tunable Diode Laser Absorption Spectroscopy (TDLAS) measurements without such constraints. A sensor robot equipped with a gimbal-mounted TDLAS unit tracks a reflector robot bearing an illuminated, color-controllable target. Coarse localization is achieved via RTK-GNSS, with vision-based fine tracking and passive time synchronization handled onboard. The system, based on off-the-shelf Pixhawk controllers and ArduPilot firmware, was validated in a 15m × 7m outdoor trial. Despite GNSS inaccuracies and deliberate occlusion by a methane-filled bag, the system retained lock, recovered from visual loss in under one second, and captured a 2800 ppm·m plume signature. These results demonstrate robust, scalable methane sensing for mobile gas tomography or standalone leak detection. Core components are released open-source to support future deployment.
Advancing Traceability of Humidity Sensors for CO₂-Based Applications Using Optical Feedback Cavity Enhanced Spectroscopy and Chilled Dew Point Hygrometers
Content : The volume fraction of humidity in gaseous feedstocks, intermediates, products, and carrier gases plays a critical role in numerous industrial processes. Two emerging areas of application are particularly noteworthy. On the one hand, there is a strategic shift towards replacing fluorinated inert gases of gas-insulated switchgear systems, and on the other hand, cost-effective humidity measurements are gaining importance in the carbon capture and storage (CCUS) applications. The accuracy of applied sensor-based systems in these contexts must be assessed with respect to the specified threshold value of the application. However, the reliability and reproducibility of the reading have to be assessed to prevent errors. Generally, humidity measurement in gaseous carbon dioxide is feasible; however, the chemical reactivity of water with CO₂ can cause significant matrix effects. If the ITS-Sonntag equation is considered to be valid in carbon dioxide, chilled mirror hygrometers can be applied for reference measurements. Further, spectroscopic methods, like optical feedback cavity enhanced absorption spectroscopy (OFCEAS), can be applied, offering another robust reference method for determining humidity volume fractions. Here, we applied OFCEAS and a chilled mirror hygrometer for reference value determination. We verified the traceability of both instruments to our in-house gravimetric gas standards containing (100.69 ± 1.564) µmol/mol water in carbon dioxide. We further applied dynamic dilution with our in-house designed humidification unit to create sample gases that contained a volume fraction of (10 to 500) µmol/mol. In these gases, verified by OFCEAS and chilled mirror hygrometer, we conducted a measurement campaign to identify and characterize matrix effects on coulometric and capacitive sensors.
The German National Hydrogen Strategy (NWS) envisions a transition towards a hydrogen-based energy grid. However, due to the material incompatibility of existing pipeline infrastructure for amounts of hydrogen higher than 10 cmol/mol, many system components of the existing grid must be replaced with significant costs and considerable time investments. Given these constraints, the admixture of hydrogen into natural gas (NG) to create a hydrogen-enriched NG blend has been designated as a transitional technology. The NWS supports this approach on a regional and time-limited basis, but clearly states that it is not intended as a permanent solution.
Nevertheless, the conversion to a fully hydrogen-based grid is expected to take several decades. During this transitional phase, precise process analytical monitoring of hydrogen amounts in the NG blend is essential to ensure both energy efficiency via calorific value control and operational safety. These procedures require cost-effective, robust, and reliable sensor technologies capable of real-time, in situ/on-site quantification of hydrogen amounts in NG.
In response to this need, we have advanced a physical sensing approach utilizing an oscillating cantilever in collaboration with Truedyne Sensor AG. This sensor system enables quantification of hydrogen amounts, direct calorific value determination as well as display of beneficial gas properties, like density, viscosity, and thermal conductivity. Moreover, the enhanced cantilever system enables direct physical sensing and can also be operated in a quasi-binary mode.
We performed comparative evaluations against two benchmark sensor systems to validate the developed technology. One utilizes chemical sensing, and the other operates on thermal conductivity measurements for hydrogen quantification. Through standardized testing, we demonstrated that the cantilever-based sensor offers both high effectiveness and competitive performance compared to current state-of-the-art technologies for accurate hydrogen detection in natural gas and precise determination of its calorific value.
In the context of digitalisation, digital calibration certificates are key to provide a fully machine-readable exchange format for metrological traceability of measurements. The most significant challenge is to establish a unique and harmonized DCC scheme, especially within the communities of specific measurement quantities. Here, we focus on the key aspect of refTypes within DCCs, and present recommendations and good practices developed by the DCC working group from the technical committee for temperature and humidity quantities within the German Calibration Service (DKD). Storage of process and quantity information relies on so called refTypeattributes which associate specific meanings to particular information in the DCC architecture. The meanings of some distinguished quantity-specific refTypes are described in this work. For various information that are specific to calibration certificates for temperature and humidity quantities, dedicated good practice implementations in XML are provided, e.g. self-heating, hysteresis as well as the calibration medium and the temperature scale used. Furthermore, the statement of the ambient conditions, that are included in almost any DCC is presented on the example of the ambient temperature.
These digitization efforts will allow to automate quality management and metrological traceability in laboratories and industrial measurement technology.
The digital product passport
(2025)
Air pollution and hazardous gas leaks remain largely invisible threats with severe impacts on health, safety, and climate. Traditional fixed monitoring networks are sparse and often miss critical hotspots, especially in complex industrial environments. Mobile Robotic Olfaction (MRO) – integrating mobile ground robots, aerial drones, and stationary sensor networks – offers a powerful approach to close these monitoring gaps. This presentation highlights recent field applications, including robotic air quality monitoring in steel factories, multimodal sensor deployments at chemical sites, and gas tomography with laser-based systems. Results show that heterogeneous sensing systems improve spatial and temporal coverage, enable more accurate leak localization, and support AI-driven analysis for real-time decision-making. Lessons learned from these deployments illustrate how MRO can enhance environmental safety, compliance, and process efficiency in real-world scenarios.