Inventors:
Joseph L. Rose - State College PA
John J. Ditri - Philadelphia PA
Frank T. Carr - Juiter FL
Jack C. Spanner - Charlotte NC
Dale Jiao - Wynnewood PA
Assignee:
Electric Power Research Institute Inc. - Palo Alto CA
International Classification:
G01N 2904
G01N 2912
Abstract:
Guided ultrasonic waves are used for the detection of defective tubes in a heat exchanger or steam generator by using a transducer which generates a guided wave at predetermined parameters of phase velocity and frequency to operate at a point on a dispersion curve which minimizes leakage of ultrasonic energy to fluid surrounding the tube. Various techniques of generating ultrasonic waves of various phase velocities such as a comb type filter allow phase velocity points on a dispersion curve to be freely selected.