Patent ID: 7168322

Claim:
A method for ultrasonic inspection of welds, comprising: a) applying the TOFD technique, 1. said TOFD technique comprising utilizing at least one pair of transducers; 2. said at least one pair of transducers comprising a first transducer and a second transducer; 3. said first transducer one emitting ultrasonic waves and said second transducer receiving ultrasonic waves; 4. said at least one pair of transducers moving in a direction selected from the group consisting of a longitudinal direction along the weld to be inspected and or a circumferential direction along the weld to be inspected; 5. said at least one pair of transducers being positioned laterally on either side of the weld to be inspected; and 6. said at least one pair of transducers comprising piezoelectric crystals or ceramics, so as to detect any flaw in the weld located at a first depth of at least about 5 mm; and b) applying a creeping wave technique, wherein said creeping wave technique comprises: 1. moving at least one third transducer along the weld to be inspected so as to detect any flaw in said weld located at a second depth of between about 0.5 mm and about 15 mm; and 2. injecting sound into at least part of the weld to be inspected with at least one longitudinal sound wave from said third transducer inclined at an angle (β) of between about 70° and 90° of an angle of refraction, or at a frequency of between about 1.5 MHz and about 4 MHz.