Figure 5-59. Example of Multiple Indications and Decrease in Multiple Back
Reflections Caused by Large Grain Size or Porosity.
When inspecting either metal parts fabricated from sheet or plate, or nonmetallic composite parts, delaminations can be
detected by noting what appears to be a reduction in the distance between back reflection multiples as shown in Figure
5-60. Actually the signals indicate multiple echoes from the delamination instead of the back surface.