Interferometric form measurement methods display ambiguities between certain form errors and the misalignment of measurement specimens. In this work, we present a concept for improving the accuracy of the form measurement of aspheres and freeform surfaces with a tilted-wave interferometer by introducing absolute distance measurements using a white light interferometer. A description of the laboratory setup and the corresponding data analysis is given together with first distance measurements.

This paper deals with the electrical investigation of various sand mixtures used in foundries for mold and core production. It is possible to classify various molding sand mixtures reproducibly on the basis of their electrical characteristics. This knowledge can now be used to develop measurement systems for processes in the foundry industry and thus increase product quality. In addition, resources can be conserved, and functioning closed-loop systems can be integrated into foundry processes.

The analysis of constructional steel structures (such as car shells for rail vehicles) in terms of (i) dimensional checking according to DIN 25043-2:2012 and (ii) completeness checking represents a challenge. The use of 3D scanners is combined with using an adapted algorithm; the respective 3D model as the target state is superimposed with difference images. These difference images show possible dimensional deviations as well as possible missing parts or, at the least, suspect points.

We present a digital holographic sensor system that is capable of measuring the complete topography of machined components with sub-micrometer precision directly inside a tooling machine. This contribution includes detailed information about the architecture of the wireless interferometric sensor HoloPort. Experimental results on milled parts show the performance of the system and illustrate possible inline applications as well as future perspectives for the sensor.

This research work suggests a method for thermal effects' compensation during the linear measurements of objects without actual temperature measurements. Due to certain simplifications, the method is not as accurate as conventional ones (when temperature of the objects and the environment should be measured), but provides much more accuracy than linear measurements without temperature measurements normally do, though maintaining the same pace.