Patent ID: 7017414

Claim:
A method of ultrasonically inspecting a disk-shaped article having a central opening and a plurality of secondary openings radially spaced outward from the central opening and circumferentially spaced from each other, the method comprising the steps of: placing at least one ultrasonic transducer in at least a first of the secondary openings of the article; performing a pulse-echo diagnostic technique on the article by causing the transducer to emit ultrasonic signals that intersect radials of the article at angles of approximately ninety degrees to the radials, the ultrasonic signals intersecting the radials at points so that a plurality of the points are located on a plurality of the radials; receiving with the transducer a reflected ultrasonic signal that is returned from at least one of the plurality of points; calibrating the amplitude of the reflected ultrasonic signal to a flat bottom hole standard reflector by causing the transducer to emit a calibration ultrasonic signal toward the central opening and receiving a reflected calibration ultrasonic signal from the central opening, and calculating a relationship between the amplitude of the reflected ultrasonic signal returned from the one point to the flat bottom hole standard reflector according to the equation: A f =λd 2 P f ( b/R ) 1/2 /(2( R−b ) P r ) where A f is the area of the flat bottom hole standard reflector, λ is the wavelength of sound in the article, d is the distance between the transducer and the at least one of the points, P f is the amplitude of the reflected ultrasonic signal from the at least one of the points, b is the radius of the central opening, R is the distance between a center of the first secondary opening and a center of the central opening along one of the radials of the article, and P r is the amplitude of the reflected calibration ultrasonic signal from the central opening.