Dashboard PAUT / Section 4: Focusing / Chapter 4: Basic Theory

Active Near-Field, Angled Wedge

Near-field with angled wedge

When an angled wedge is used, the composite near-field can be calculated with the following formula:

  1. A 60° beam is created with 16 elements of 1 mm
  2. According to Snell’s law, the angle of the beam in the wedge is 38.5°.
  3. The wedge is cut at a 36° angle
  4. The active aperture is corrected for the beam angle in the wedge and part. The factor k is calculated
  5. For a 5 MHz probe and a wedge path of 28 mm, the maximum near-field for the 60° beam is calculated
  6. The maximum near-field length in steel for the 60° beam is 41.2 mm

The effective aperture must be corrected for each angle.