Preparatory Notes for ASNT NDT Level III Examination - Ultrasonic Testing, UT

Practice Makes Perfect
52. One of the most apparent characteristics of a discontinuity echo, as
opposed to a non-relevant indication is:
(a) Lack of repeatability
(b) Sharp, distinct signal
(c) Stable position with fixed transducer position
(d) High noise level
58. What useful purpose may be served by maintaining grass on the baseline?
(a) To estimate casting grain size
(b) To provide a reference for estimating signal to noise ratio
(c) To verify adequate coupling to the test piece
(d) All of the above