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.

In order to differentiate between a wet and a dry road surface, the water film height should be measured by using an infrared-based sensor system. By means of different wavelengths, it is also possible to distinguish between ice and water. In this article, a sensor system for the determination of the physical state of water on different surfaces using infrared LEDs and one photodiode is presented. This shall serve as a basis for the calculation of the road condition.