Question

When performing weld inspections with time of flight diffraction (TOFD):

A) a single scan can be performed that will detect all discontinuities from shallow surface discontinuities to lack of fusion or porosity
B) the appropriate angle must be selected to be perpendicular to the weld preparation angle
C) mid-wall discontinuities can be detected and sized even if they are not oriented perpendicular to the sound beam
D) the reference level must be set accurately since indication evaluation is based primarily from signal amplitude

Answer 1

TOFD is a technique used for weld inspections. It can detect various discontinuities and has specific requirements for angles and reference levels.

Step-by-step explanation:

Time of flight diffraction (TOFD) is a technique used for weld inspections. When performing TOFD, the following statements hold true:

1. A single scan can be performed that will detect all discontinuities from shallow surface discontinuities to lack of fusion or porosity.
2. The appropriate angle must be selected to be perpendicular to the weld preparation angle.
3. Mid-wall discontinuities can be detected and sized even if they are not oriented perpendicular to the sound beam.
4. The reference level must be set accurately since indication evaluation is based primarily on signal amplitude.