Is TOFD Blind for ID and OD Surfaces?

TOFD (Time of Flight Diffraction) is a new post modern technology in nondestructive testing, NDT. It is based on the diffraction phenomena of sound rather than reflection which is used in classical ultrasonic testing. One of the major applications of TOFD in industry is the ultrasonic examination of welds. While doing so, one should choose the most convenient ultrasonic configuration (i.e.different probe angles, probe center spacing, frequencies and diameters) in conjunction with the material being tested. The goal of this article is to emphasize the effectiveness of this method on top surface (ID) and bottom surface (OD) of welds.

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