Enhanced Visual Techniques

The Edge of Light(tm) (EOL) enhanced optical technique is a ground-breaking approach to non-destructive inspection (NDI). It works by converting changes in surface slope into light intensity variation in an image. For many applications, Edge of Light performs better than inspections using liquid penetrant, magnetic particle, ultrasonic inspections, or optical microscopy.

A portable D Sight Aircraft Inspection System (DAIS) with digitized imaging capability for field and laboratory applications is available. Diffracto Inc of Windsor, Ontario in collaboration with IAR has developed three commercial DAIS systems. The IAR operates the two corrosion systems and a number of experimental systems for composites inspections.

IAR has begun development of a proprietary solid film highlighting technique (SolidHi(tm)) which is complementary in the use of both D Sight and EOL. SolidHi replaces the use of liquids as a temporary highlighting method and saves the subject surface from contamination while providing a uniform and repeatable reflective surface. The technique uses:

• shadow Moiré to observe surface out-of-plane deformations
• video microscope for viewing surface-breaking flaws
• scanning electron microscope for study of fracture surfaces
• replica technique for viewing, imaging and recording surface features
• boroscope for viewing internal surfaces.

A lap splice joint from a Boeing 727, as seen by the unaided eye (bottom) and by an Edge of Light scanner (top). Pillowing due to corrosion is evident in much of the Edge of Light image, particularly at the left.

Related Information

Institutes:

• NRC Institute for Aerospace Research