Guided waves are a large portfolio of techniques based on the propagation of modes with concentrated energy near a boundary or between parallel boundaries and that has a direction of propagation parallel to these boundaries. With this in mind, guided waves present great potential for medium and long-range inspection of structures such as pipelines and piping systems in the oil and gas industry. The available techniques are LRUT and MRUT, these have large area of applications such as screening for corrosion under insulation, under pipe supports, hidden areas, and more generically bare pipes with generalized corrosion.

The amplitude of the reflected sound energy is influenced by the cross-sectional area loss and its circumferential extent and varying depth along its axial extent. In this paper, we intend to demonstrate the effectiveness of the signal Area Under the Curve to assess the corrosion Axial and Circumferential extent. Applied to large defect database, the technique has potential to classify and size the areas of corrosion.