Abstract: Methods and systems for inspecting a generator rotor is provided. The system includes a phased-array ultrasound transducer that includes an active face including a plurality of transducer elements formed in an array, the elements are configured to be excited in a predetermined sequence to generate a transmission beam of ultrasound energy at a plurality of angles with respect to the active face. The elements are configured to receive ultrasound echoes through the active face. The system also includes a transducer wedge including a coupling face configured to couple to the transducer and a transmission face configured to couple to the rotor. The wedge is configured to refract the ultrasound transmission beam at a predetermined angle at the transmission face such that the beam enters the component at an angle substantially normal to a load surface of the rotor.

Abstract: A method for ultrasonically inspecting a generator field tooth for the detection, characterization and/or sizing of cracks thereat is disclosed. A monolithic piezoelectric transducer (MPT) productive of a test signal having a defined angle of refraction with respect to the tooth material is selected. The MPT is positioned at an outer surface of the tooth and oriented so as to direct the test signal to propagate through the tooth toward a load surface of the tooth where a butt joint of a set of wedges is disposed. The MPT is activated so as to test the load surface proximate the butt joint for cracks thereat.

Abstract: A method for ultrasonically inspecting a generator field tooth for the detection, characterization and/or sizing of cracks thereat is disclosed. An electromagnetic acoustic transducer (EMAT) productive of a test signal having a defined angle of refraction with respect to the tooth material is selected. The EMAT is positioned at an outer surface of the tooth absent a fluid couplant and oriented so as to direct the test signal to propagate through the tooth toward a load surface of the tooth where a butt joint of a set of wedges is disposed. The EMAT is activated so as to test the load surface proximate the butt joint for cracks thereat.