Patent ID: 8746070

Claim:
A method for inspecting a cylindrical tubular structure ( 240 ) characterized by an inside diameter and an outside diameter, the method comprising the steps of: providing a phased array ultrasound flaw detection system including a detector electrically connected to a transducer ( 220 ), said transducer mounted to an upper surface of a wedge ( 200 ), said wedge having a lower concave surface ( 202 ); providing a reference plate ( 400 ) having a flat surface; abutting said concave surface of said wedge against said flat surface of said reference plate thereby defining an interstice between said concave surface and said flat surface; filling said interstice with a sonic couplant; calibrating said flaw detection system while said interstice is filled with said sonic couplant; coating said structure with said sonic couplant; disposing said concave surface of said wedge against said coated structure at a first point; introducing an ultrasound wavefront generated at said transducer through said wedge into said coated structure; sweeping said ultrasound wavefront through a plurality of incidence angles including a preferred incidence angle that is defined by the inverse sine of said inside diameter divided by said outside diameter; measuring an echo return signal of said ultrasound wavefront received at said transducer at each of said plurality of incidence angles; displaying all of said measured echo return signal received at said preferred incidence angle in an A-scan format ( 110 ) on said detector while simultaneously displaying at least part of said measured echo return signals received at all of said plurality of incidence angles in an S-scan format ( 120 ) on said detector; then moving said concave surface of said wedge against said coated structure to a second point; and repeating said steps of introducing, sweeping, measuring, and displaying at said second point.