For various applications, the entire work piece geometry must be dimensionally analyzed. To document the quality of a mold for plastic injection molded parts, for example, a sample part must be measured completely (first article inspection). Particularly for medical component applications, revalidation of all component dimensions must be performed at specified intervals or for any process changes such as new material lots. Similar processes are used in light alloy casting and many other production methods.  Completing these tasks with classic tactile or multisensor coordinate measuring machines requires significant time. With these machines, the measurement time directly depends on the number of features and is therefore very long for a large number of features. Fast coordinate measuring machines with image processing sensors, for example, measure a few or at maximum multiples of ten dimensions per second, while tactile machines can achieve only a few dimensions per minute. With multisensor coordinate measuring machines, the mixed use of various sensors means that the time required is somewhere in between.  For coordinate measuring machines with X-ray tomography, the measurement time is independent of the number of features to be analyzed. With typical measurement times in the range of 10 to 60 minutes for tomography “in the image”, the economic advantages of these machines are obvious when measuring many dimensions.

Seen in the image above:  Schematic representation of measurement time of coordinate measuring machines (CMM) as a function of the amount of features for different types of sensors:  a) Tactile only (3D) b) Multisensor (3D) c) X-ray tomography (3D) d) Image processing CMM (2D)