Measuring three-dimensional surfaces with small 3D structures is a challenge for industrial measurement technology. Common optical procedures such as stripe reflection, laser triangulation or white-light interferometry are too imprecise, too slow or insufficiently robust for many inline measuring assignments. The HoloTop measuring system developed at Fraunhofer IPM uses digital multiwavelength holography for rapid 3D inline inspection. Today holographic measurement processes are primarily used in microscopy in the laboratory. In contrast to this, the sensors developed by Fraunhofer IPM can be used to measure an area of 20 mm x 20 mm. Here the sensors measure the topography of surfaces from the micrometer to the millimeter range – and do so with unprecedented speed and robustness.
100 percent production control for precision turned parts
On behalf of Werner Gießler GmbH Fraunhofer IPM developed a fully automated inline inspection system for precision turned parts. At second intervals, the system inspects the sealing faces of precision turned parts no larger than a thumbnail – these faces being found in 70 percent of the common rail injection systems of truck diesel engines worldwide.