| 摘要 |
A compound ultrasonic scan of an object is effected with a pair of transducers mounted adjacent to the object but spaced apart from each other. Each transducer is operated as a "wobbler" transducer. That is, the transducer transmits pulses of ultrasonic energy into the object and receives echoes from acoustic discontinuities in the object while the transducer is oscillated mechanically, through a predetermined angle, about an axis which passes through the transducer. The improvement of this invention is (i) the oscillation of the transducers is synchronism with each other but out of phase with each other, so that when one transducer is at the edge of its angular scan, the other transducer is at the center of its angular scan, and (ii) activating the transducers using a stream of electrical pulses which are supplied to the transducers so that when a transducer is at the center of its angular scan, it receives most of the activating pulses and when it is at the edge of its angular scan, it receives a small proportion of the activating pulses.
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