Method and apparatus for mapping the wall thickness of tubes during production

摘要

An apparatus and method for mapping out wall thickness of a tube or other object having motion in two directions. The device includes a first laser for generating ultrasound propagating inside tube wall over a particular generation spot on a surface of the tube, a second laser coupled to an interferometer for detecting produced ultrasonic echoes over a detection spot on the surface. A processor is provided for operating on recorded ultrasonic echoes and using a given value of ultrasonic velocity and the distance between the generation spot and the detection spots for determining wall thickness at a mid-point between the generation and detection spot. An optical displacement measuring device determines a displacement in two dimensions between the generation spot and arbitrary starting spot and a display for displaying wall thickness values over the surface of the tube.