Operating Manual

Fig. 3: Automatic porosity analysis of an automotive casting. The distribution of differently sized pores within the entire cast part can be

shown in different colours.

4. High-Resolution CT-Based 3D Metrology

Due to the large number of internal contours in cast parts made from plastic or light alloys, the

use of conventional measurement methods to inspect such parts is often not possible in a non-

destructive way and takes a considerable amount of time. The fact that CT offers extremely

precise and complete 3D representation of objects opens up its field of application, meaning

that it is also suitable for coordinate measuring. This is because, in contrast to conventional

tactile or optical coordinate measuring systems, CT measuring systems are also able to

completely capture the hidden contours of specimens, such as cavities and undercuts. In

addition, a CT scan of a specimen results in a very high number of measurement points,

typically in the order of magnitude of 10

to 10

, which can then be used (through the

application of statistical methods) to achieve a measurement resolution that is typically

significantly below 1/10 of the voxel size (voxel = volumetric pixel); which, depending on the

object size, is within the micrometer range.

Fig. 4 shows, by way of an example, a target/actual comparison of the variances between a

specimen and the CAD model. The swiftly generated results from these measurements can be

used as a basis for correcting the manufacturing process in a timely manner and optimizing

series production.

Fig. 4: Using false colour image display to compare the measurement data and CAD model allows a qualitative

judgment to be made quickly regarding the production quality of the casting.