Method and Device for Checking the Wall of a Pipeline for Flaws

Abstract

The present disclosure relates to a method for detecting a defect (16) in a pipeline wall (14) and a pipeline inspection device for being inserted into a pipeline. The method comprises the steps of arranging a first ultrasonic transducer (10) inside a pipeline at a finite stand-off distance (d-i) from the pipeline wall (14); emitting, by the first ultrasonic transducer (10), a first ultrasonic signal towards the pipeline wall (14) at a finite angle (a) relative to a normal of the pipeline wall (14), wherein the first ultrasonic signal excites at least one fundamental Lamb mode in the pipeline wall (14); and receiving, by the first ultrasonic transducer (10), a second ultrasonic signal from the surface of the pipeline wall (14), wherein the second ultrasonic signal is an echo signal generated by the at least one fundamental Lamb mode excited by the first ultrasonic signal and reflected from a defect (16) in the pipeline wall (14).

Dependencies are inferred from the claim text.