Dashboard UT / Section 2: 0-degree / Chapter 4: Basic Theory

Shallow Indication

Shallow Indication

In this example, a large probe is positioned above a block with a shallow lamination. The result is multiple echoes from the lamination within the thickness of the material.

  1. The wave front is emitted and start its travel in the wedge
  2. At the wedge/material interface part of the energy is reflected towards the probe and part enters the material. The wave front traveling in the material splits at the top of the lamination
  3. The order in which the echoes reach the probe is as follow:

    • First wedge echo
    • First lamination echo
    • Second lamination echo
    • Third lamination echo
    • First backwall echo
    • Fourth lamination echo

The loss of amplitude between echoes from the lamination is due in part to scattering but also because part of the energy is returning to the probe at every bounce.