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Flatness and contour measurement of sheets

alpha.fi compact

Typical rough plate metal, for instance for large pipes, pipelines, mobile cranes, ships and platforms for wind power plants with its dimensions of several 10 square meters has a total weight of several tons. The most frequent reason for reclamation is a quality requirement which has not been complied with. 

The geometry of every manufactured metal sheet in the production line is subjected to contactless inspection by an automatic flatness measuring system. The geometry measurements include sheet length, width, contour and angularity - and flatness measured over the surface area, a capability that conventional systems do not provide so far. alpha.fi compact is generally laid out for measuring up to 3,200 mm wide and up to 6,000 mm long products. The system can be scaled up for measuring also much larger sheets, as used in aircraft construction, for example. Sheets of any – also non-rectangular – shape can be measured, even if they are foil or paper-clad.

Contours can be measured with an accuracy of ± 0.1 mm, surface flatness with an accuracy of ± 0.025 mm. The systems are MSA capable measuring equipment, meaning that they can be used to verify that products comply with DIN standards and to control and audit production processes.


nokra flatness and contour measurement means:

  • automatic 100 % measurement and complete documentation
  • automatic classification of flatness defects
    - measurement of flatness at ± 0.025 mm
    - measurement accuracy for contour up to ± 0.1 mm
  • width-independent measuring time is only a few seconds
  • Optimization of upstream production processes
  • Can also be used in hot strip production
  • Maintenance-free
  • Insensitivity to extraneous light 
  • Flexibility with different scattering properties of the surfaces to be inspected

High-density measurement data

A 3D presentation shows the contactless measured flatness and contour of each sheet manufactured in the production line. After the passage it is directly shown on the control panel. Through feedback of the measurement results into the process management additional cost-intensive er-rors in the production are avoided. nokra’s flatness measuring systems are fitted with an automatic function for adjusting and monitoring (measuring capability proof in accordance with DIN EN ISO 9001).