Surface Inspection

Surface defects can have a significant negative impact on a product’s functional characteristics and reduce the credibility of products.

Porosity, cracks, marks and other challenges on the surface

Detecting different surface defects is one of the most demanding inspections encountered. Our solutions can detect in high speed even very small surface defects measuring tens of microns, that can be can only be detected by a change in the relief.

For high resolution detection, we use special optical and lighting systems and hybrid 3D technologies (laser scanning, collimated illumination, and Shape-from-Shading).

Advantages and benefits:

100% production control

Very high resolution of the captured image

High system flexibility

Picture acquisition during high speed movement

Types of Defects:

  • Visual surface defects
    • Stains, dirt, rust
    • Handling marks, scratches
    • Traces of deposits and phosphates
    • Traces of machining; grooves
  • Spatial surface defects
    • Porosity
    • Bruises
    • Missing material
    • Cracks
  • Inspection of shape and dimensions
  • Presence of holes, rivets, nuts, threads, etc.

System Parameters:

Camera system resolution: From 10 µm
Material scanning speed: Up to 1,000 mm/sec
Size of the smallest detectable defect: From 50 µm (depending on application)
Speed of evaluation and sorting: > 10 pcs/sec. (depending on application)
Number of cameras per station: Up to 8
Size of the database of sorting programs: Unlimited

Method of Measurement

Surface defects are detected mainly with 2D camera systems. They mostly utilize line scan cameras for better integration, higher overall image resolution, and very homogeneous illumination.

A key task is to configure the lighting to empathize the defects and suppress common surface structure. Here, the following lighting configurations are mainly applied:

  • Diffusion – to detect contrasting defects (dirt, rust)
  • Collimated – to detect changes in the shape of the surface, non-contrasting
  • Low-angle – to detect cracks, burrs, porosity, missing material
  • Infrared – to eliminate pigments and printing

Special Applications

Surface checks include the running of special applications covering the following areas:

  • Optoband – bearing raceway surface inspection
  • BoreView 360 - inside brake cylinder grooves
  • Checking for plastic foil defects
  • Checking clutch and brake linings
  • Separate interoperable sorting device
  • Inline device integrated in the production process
  • Continuous measurement of products on conveyors
  • Discrete rotary system measurements
  • Sensors integrated into the assembly station
  • Scanning of static products