To improve the energy efficiency of industrial processes, such as continuous steel casting, lab-scale experiments with liquid metals are performed. We present an ultrasound Doppler signal process for multiplane, high-frame-rate flow imaging. We achieve real-time operations with an efficient implementation in a field-programmable gate array (FPGA). We analyze the contributions to the uncertainty of the velocity measurement and relate it to its fundamental limit.

This paper introduces a new method to drastically reduce the anisotropic strain sensitivity of granular thin film strain gauges. As a result, these improved strain gauges produce a much higher sensor signal when used for force transducers with biaxial strain fields. This gauge type is also more advantageous for uniaxial stress measurements. The method is based on the creation of a certain topographic structure of the strain gauges; in our case, this was realized by a picosecond laser system.

Photoelasticity is considered a useful measurement tool for non-destructive and contactless determination of mechanical stresses or strains in the production of silicon wafers. In this work, a detailed derivation for the anisotropic stress-optic law is presented, and the corresponding stress-optical parameters are measured.

A completely new evaluation method for optical sensors is investigated in this paper. It originates from research that integrates optical sensors into radio-over-fibre networks. The laboratory-based experimental set-up is explained, and the findings are validated by a comparison to the conventional evaluation scheme. Finally, the work provides a detailed mathematical model to understand the implications of this new read-out method for practical applications.

Distributed fiber optic strain measurement based on Rayleigh scattering enables the monitoring of strain along the entire fiber length and the possibility of integration into material matrices. In this article, optical fibers were integrated into the concrete matrix of small prisms to measure the deformation by drying. In comparison with a reference measuring method, the losses of strain transfer were measured. The analysis shows a high correlation between the reference method and the fiber.

European EMPIR project MicroProbes aims to use large-cale tactile microprobes for contact resonance applications, an established measurement mode of atomic force microscopes (AFMs). Because of the size of these probes, some of the simplifications made for AFM probes are not applicable. This study presents a guide on how to systematically create a model that replicates the dynamic behavior of microprobes. The finished model is then verified by analyzing a series of measurements.

This article presents a classification concept based on deep learning as an additional optical test method for real-time visualization and analysis of electrical assemblies in the production environment. For this purpose, a neural convolutional network is used to identify the quality of the solder joint of surface-mounted chip components in the inspection images. The concept can be used to increase the detection performance of the solder joint inspection systems.

For the determination of the refractive index of the lubricant used in the sheet-bulk metal forming process, a lubricant thin-film thickness standard was developed which represents a continuous measuring range from 6 to 100 μm. To determine the refractive index, the thin-film thickness standard was measured with a coaxial interferometric measurement system in various thickness ranges. The results show changing optical properties with increasing layer thickness.

Detecting faults in bearings is indispensable for the maintenance of many industrial machines or components. The faults are detected by recognizing patterns in vibration data that are measured at the bearing housing. The method can be trained with data of variable revolution speeds, therefore reducing the effort for the acquisition of training data. Moreover, incipient faults can be detected before they cause severe damage to the equipment.