In coordinate measuring technology with computed tomography (CT), the dimensional analysis of work pieces made of multiple materials is particularly challenging. Werth Messtechnik has developed a unique solution.

Multi-material work pieces are often metal and plastic components, such as assembled plug connectors. The measurement task is typically to determine the position and bend angle of the internal metal pins. In a CT measurement, however, the metal pins often cause artifacts due to beam hardening and scattered radiation. Historically these effects made the measurement of the plastic enclosure much more difficult. With Multi-Spectra-CT, Werth Messtechnik offers an innovative solution for work pieces made of multiple materials. The WinWerth® measurement software takes two CT measurements with spectra tuned to a specific material and computationally combines them into a single volume. This volume can be used to check dimensions in any desired cross section using 2D contour image processing. A method for local edge detection can also be used to derive a 3D point cloud for the entire work piece. By reducing the artifacts in the volume, dimensions measured between the different materials have lower measurement uncertainty.