A computer-based ultrasonic (UT) inspection system has been developed which provides a method for locating and sizing flaws in the near-bore region of steam turbine rotors. Components from various manufacturers were integrated to make up this unique test system.

Shear wave inspections are performed utilizing an expandable test head coupled to a positioner via geared extension bars. The head accepts up to three transducers while the positioner provides the axial indexing and circumferential rotation of the transducers.

A microprocessor is supplied with signal information from a multichannel UT instrument and location information (axial and circumferential for each transducer) from the positioner. All recorded data are transferred from the computer memory to floppy disks, thus maintaining a historical record of all test results.

Upon completion of each UT inspection scan, a color video monitor with graphic display allows for evaluation of test data utilizing several software programs which are presently available. A color printer supplies a hard copy of inspection results.

A visible magnetic particle (MT) examination is performed from the bore to provide additional information on surface and near-surface flaws. This boremag inspection is accomplished using the positioner with extension bars and a miniaturized TV camera with a light source and mirror. The camera outputs to a video recorder and a video monitor.

The UT and MT inspections provide a data base which can be used for evaluating turbine rotor integrity and monitoring flaw propagation. With the addition of new software and a different type positioner, the basic ultrasonic hardware can be used for inspection of brazed joints in sleeved steam generator tubes. Other possible applications of this system (UT on piping, eddy current in tubing, etc.) are discussed.