Extruded profiles are semi-finished products (made out of steel, brass, aluminum, synthetics...) which are appointed for
wide applications in manufacturing of technical products. As yet used optical sensors in process control working to the
shading technology detect the object's shadow orthographically to the axis of illumination. As a consequence they record
it unattached by the profiles coat in measurement range at any point of the measured profile with high precision. As a
matter of fact, concave zones cannot be captured. Alternatively the measurement of concave zones can be arranged by
light-section systems. These do not comply with the required accuracy, are comparatively slow and moreover affected by
dislocations of the section of the profile. A measurement system including a light-section and a shading system combines
the advantages of both optical systems. It is to serve with a reliable conception for the assembly of a bi-sensorial
measurement system consisting of both systems as well as suitable methods of analysis for the in-line inspection of
concave profiles. As a result it contains conclusions concerning requirements of the light source, the arrangement of this
source and the cameras, obtainable precision and sampling rate as well as the essential synchronization of both systems.
After designing an appropriate prototype, the selected light-section system and the shading system will be synchronized
and aligned. Therefore, the metered geometrical data will be merged for the evaluation of form deviation. So, developed
and adapted software supports and contains proposals to the uncertainty after successful tests. The system and a
calibration method will be proved in production where robustness will be a most critical despite of heat, dust and
vibrations. The target uncertainty of less than 0.1 mm at every section of the profiles coat has to be met.