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.

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.

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 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.

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 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.