Patent ID: 7019520

Claim:
A method for inspection of heat exchanger tubes using reflected torsional waves, comprising the steps of: inserting a cylindrical waveguide probe into an open end of a heat exchanger tube, a coupled end of the waveguide probe being located a distance from the open end by at least the distance from the open end to a heat exchanger tube sheet; applying an electronic transmit pulse to a magnetostrictive sensor mounted on the waveguide probe; generating and transmitting a torsional wave pulse in the waveguide probe by the magnetostrictive sensor; coupling the transmitted torsional wave from the waveguide probe to an inside wall of the heat exchanger tube for propagation along the length of the heat exchanger tube; coupling reflected torsional wave signals from defects and a far end of the heat exchanger tube to the waveguide probe; sensing the reflected torsional wave signals by a magnetostrictive sensor; and electronically processing the sensed signals for determining a location and characteristics of the defects in the heat exchanger tube walls.