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Synchronization problems within distributed sensor networks are a major challenge in the field of Industry 4.0. In this paper, artificially generated time shifts between sensor data and their influence on remaining useful lifetime prediction of electromechanical cylinders are investigated. It is shown that time shifts within sensor data lead to poor remaining useful lifetime predictions. However, this prediction can be significantly improved using various methods as shown in this contribution.

During the geometric calibration of infrared cameras, the parameters that describe where object points are mapped onto thermal images are determined. The required reference data is obtained by capturing so-called calibration targets. In established approaches, it is difficult to estimate the lens distortions precisely. A newly developed target and its evaluation algorithm make it possible to increase the sensitivity of the calibration by finding reference points close to image borders.

Bees play a major role in our ecosystem and the human food supply chain. Numerous threats, from pesticides to parasites, endanger bees and possibly cause bee colony collapse. The Varroa mite is one major parasite, and its timely detection and treatment is a key task for beekeepers. Contemporary sensors, electronics, and AI/PR allow vital parameters of bee hives to be monitored. Recent gas sensors (e.g., SGP30 or BME680) allow continuous in-hive parameter and Varroa population monitoring.

The publication contributes to a uniform procedure for in-process measurement data acquisition in additive manufacturing, which is essential for a controlled correction of detected manufacturing deviations. The developed methodology is based on an analysis of the melt pool contours relative to a referencing system integrated in the powder bed. By recording the referenced melt pool and the shimmering contours after powder application, manufacturing deviations can be evaluated more accurately.

A novel experience replay particle swarm optimization algorithm is presented and successfully deployed to improve the optimization performance for reconfigurable analog integrated circuits of industry 4.0. An optimization approach is introduced that relied on THD-based indirect measurement method that varies from the traditional calibration approach. Instead, the proposed calibration methodology optimizes all characteristics of the reconfigurable amplifier at once.

We developed a smart in-cylinder pressure sensor for closed-loop combustion control. The sensor concept is based on a robust and reliable steel membrane equipped with highly strain-sensitive and temperature-stable thin films. The sensor system is complemented by a smart electronics allowing real-time data processing for calculation of different combustion parameters. The data are utilized to control the igniting timing of a spark plug for efficient operation of a combustion engine.

We investigated the feasibility of indium tin oxide (ITO) as an alternative plasmonic material to replace noble metals for sensing applications in the mid-infrared region. An ITO-based plasmonic slot waveguide was numerically designed and analysed for a wavelength of 4.26 µm, which is the absorption band of CO₂. As the proposed structure shows low propagation lengths, we concluded that ITO appears not to be an appropriate candidate for plasmonic waveguiding systems.

In order to contribute to a standardisation and process monitoring of additive manufacturing (AM) processes, a novel referencing approach was developed to improve the assessment of geometric manufacturing and measurement deviations. This is based on a referencing system integrated in the powder bed, which enables a shortening of the measuring loop. The position-stable quartz glass pipes enable more precise specification of lateral manufacturing and measurement deviations during AM.

The development of optical design is characterized by the desire for more applications and better performance. The latest result of this development is freeform optics offering almost unlimited possibilities for the designers. However, an optical component has also to be manufactured and tested by metrology. We propose a measurement technique for the surface characterization of freeform optical components and highlight the possible error sources and their influence on the measurement result.

The method of non-contact temperature measurement in conjunction with a 3D sensor described in this paper can be used to determine the heat loss of technical devices and industrial plants. This measurement tool thus helps to optimize the energy efficiency of these devices and plants.

Temperature sensors based on piezoelectric devices enable precise measurement of temperature changes in harsh environments such as high temperatures or aggressive atmospheres. In the case of this device, the change in the temperature is detected by means of the changing resonance frequency of the sensor. Here a sensor device based on catangasite (an isomorph of quartz) is presented. We discuss its behavior at elevated temperatures and confirm that it can successfully operate up to 1030 °C.

The paper presents a concept for an automated classification of machine-readable data from measurement according to its agreement with metrological guidelines. An implementation of the classification was realized within the TraCIM online validation system for trustworthy certification of software that is under quality management. The research was collaboratively made by the partners of the European Metrology Research Project SmartCom.

A setup for the characterization of liquids with the perspective of monitoring crystallization processes is presented. The novelty of this setup is the realization of viscosity and conductivity measurements using two quartz crystal microbalances. Additionally, there is the possibility to apply an electric field through the sample, enabling the manipulation of charged particles. The results show that the measured values are in reasonable agreement with values from the literature or standards.

The Physikalisch-Technische Bundesanstalt calibrated pyroelectric detectors at two independent primary radiometric standards regarding their spectral responsivity. The SI traceable measurements in the spectral range between 1.5 and 14 µm are consistent within the measurement uncertainty in the range of 1 % and 14 %. The importance of the correct read-out of lock-in amplifiers and the accurate consideration of the temporal shape of the chopped radiant flux behind the chopper wheel are shown.

We develop sensor material to effectively transform mechanical force or torque into an electrical resistance. A new type of thin films containing nickel and carbon has a significantly higher output and is thus very advantageous. But so far, the electrical resistance lacks stability. We therefore investigate how to stabilize the material and show that the partial replacement of nickel by the element chromium solves the problem. The optimized sensor films are now suitable for widespread use.

The paper proposes a structure for the creation of new simulation software for uncertainty estimation. The structure was derived from the well-established VCMM. To make it easy to apply the software structure to specific projects, a supporting software library (written in C++) was created. The library provides all the components necessary to create software for uncertainty estimation. The software structure and library proposed can be used in different domains of metrology.

This work shows a possibility of assembly and connection technology for use under high temperatures up to 1000 °C. A packaging concept was developed, and all the necessary material and joining technologies have been verified to be suitable for use at 1000 °C. A working sensor was built and measured in comparison to the resonator alone. All packaging materials and structures were measured electrically and dielectrically. Equivalent circuits for the packages up to 2 MHz and 1000 °C are available.

An adjustment concept for high-precision weighing cells has been developed and experimentally investigated. It allows for minimization of uncertainty contributions due to tilt while maximizing sensitivity to mass. By applying the adjustment capabilities to new weighing cells, the devices can simultaneously become more accurate, more adaptable and more robust.

A newly developed experimental setup to characterize thin polymeric films during dehydration and hydration is presented. The great advantage of this measurement device and technique is that it monitors the mass change and conductivity of the films in situ and simultaneously at virtually identical conditions. The feasibility of the technique is demonstrated by characterizing ionomer thin films. A mass resolution of ±7.9 ng is achieved. The precision of relative humidity (RH) control is ±0.15 %.

The present research work investigated the acoustic manipulation of bioparticles and cells in closed and liquid-filled vessels using a special method for focusing acoustic fields. Based on simulation studies, the feasibility of particle manipulation with this method was successfully demonstrated. Successful final testing using a demonstrator and thus the transfer and prospective application in biotechnology are part of further research work.

A homemade experimental setup was developed using actuators and temperature sensors monitored by Arduino platforms to characterize thermal behaviors of composite panels containing phase-change materials (PCMs). The characterization is based on modeling steady-state thermal conduction and natural convection heat transfer. Temperature measurements allow for obtaining effective thermal conductivity, phase shift time, and energy storage capacity of composite panels incorporating PCMs.

It is a great challenge to apply a diagnostic system to engine test beds. The main problem is that such test beds involve frequent configuration changes. Therefore, the diagnostic system must be highly adaptable. A modular toolbox-based approach combines physics-based and data-driven modeling concepts and, thus, enables highly flexible application. Adaptability and detection quality are validated using measurement data from a single-cylinder engine and a multicylinder engine.

In this contribution the frequency domain fluorescence lifetime imaging microscopy (FD-FLIM) technique is evaluated for post-consumer wood sorting. The measured data were processed using algorithmic decision trees to identify the wood species and post-consumer wood category. The experimental results revealed the high potential of the FD-FLIM technique for automated post-consumer wood sorting.

Gas analysis by absorption spectroscopy helps to optimize combustion processes in engines. Optical distance sensors are non-contact and offer high accuracy and precision. Both sensor applications benefit from light sources with a rapidly swept wavelength to monitor dynamic processes. In our paper, we precisely characterize the dynamic wavelength sweep of a rapidly pulsed VCSEL (vertical cavity surface emitting laser), a tiny semiconductor laser well suited for optical sensing.

Modern production concepts generate a demand for reliable, energy-efficient, fast, and secure wireless communication solutions. Therefore, the current consumption should not increase substantially due to additional security operations. This paper shows a principle current measurement method that is exemplary of a transceiver for IO-Link Wireless protocol. The results show that the current consumption only increases slightly with acceptable measurement uncertainty.

Acceptance and reverification testing for industrial CT systems is described in different standards. The characterisation and testing of CT system performance are often achieved with test artefacts containing spheres. This simulative study characterises the influence of different geometrical error sources – or geometrical misalignments – on these sphere measurements.

In this paper, a near-infrared LED system is proposed for autonomous vehicles to distinguish between weather-induced road surface conditions (dry, wet, snow, ice, water). For the LED spectra, the influence of the LED bandwidth is investigated. To assess the performance of the system for a long detection range, experiments with large incident angles are conducted. The feasibility of this system is proved via a laboratory experiment with three near-infrared LEDs and a camera.

We describe the development and characterization of a three-dimensional (3D) magnetic coil system that is able to produce magnetic flux densities of up to 2 mT in an arbitrary field direction. The coil system can be used to calibrate 3D magnetometers efficiently, and the measurements are traceable to national SI units.

The measurement principle shows how to measure calibration torque moment shunts in a 5 MN m torque standard machine using an interferometer and hinge flexure stiffness. The analysis of the measurement uncertainty influences shows that the measurement uncertainty of transversal force measurement ranges from 0.61 % to 3.04 % and stays constant at 1.7 % for torque measurement. A FE validation was performed. The measurement uncertainty of the calibration torque moment sank from 0.106 % to 0.100 %.

Industrial X-ray computed tomography is a holistic measurement technique for dimensional metrology. However, the relatively long measurement time is a hindrance to its application. A possibility to reduce measurement times, the continuous scan mode, is characterized in this work. The question is how much the time reduction impacts the accuracy of the dimensional measurements. The core result of the paper is an estimate of the effect along with experimental proof that this estimate is reasonable.