Nondestructive ultrasonic transducer

Abstract

An extendable probe that permits nondestructive ultrasonic inspection of a workpiece for flaws is disclosed which provides information indicative of flaw presence and location. The probe includes a pair of waveguides capable of elastic wave transmission. A first waveguide is excited to produce elastic waves which travel along the waveguide to an end of the waveguide in elastic wave transmitting contact with the surface of the workpiece under inspection. A second waveguide is maintained in contact with the workpiece a selected distance from the first waveguide and a sensor is disposed on the second waveguide for reception of elastic waves. In the absence of workpiece defects intermediate the contact points of the first and second waveguides, elastic waves are transmitted from the first waveguide to the second waveguide through the workpiece to the sensor and an output signal representative of transmitted elastic waves is produced by the sensor. The presence of a crack or flaw in the workpiece between or proximate to respective ends of the waveguides is apparent as a variation in the amplitude of the sensor output signal. Inspection of relatively inaccessible remote surfaces is facilitated with the probe which is thin and extendable. The distance from the sensors to a workpiece flaw is determinable from travel time of elastic waves in the waveguides and the workpiece. Detection of flaws of varied orientation in the workpiece is achieved by pivotable orientation of the waveguide ends with respect to the workpiece.