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

Preparatory Notes for ASNT NDT Level III Examination - Ultrasonic Testing

Preparatory Notes for ASNT NDT Level III Examination - Ultrasonic Testing

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27. Using the immersion method, a distance amplitude curve (DAC) <strong>for</strong> a 19<br />

mm (0.75 in) diameter, 5 MHz transducer shows the high point of the DAC at<br />

the B/51 mm (2 in) block. One day later, the high point of the DAC <strong>for</strong> the<br />

same transducer is at the J/102 mm (4 in) block. Assuming that calibration<br />

has not changed, this would indicate that the transducer:<br />

A. Is improving in resolution<br />

B. Is becoming defective<br />

C. Has the beam of a smaller transducer<br />

D. Both B and C (?)<br />

28. What law can be used to calculate the angle of refraction within a metal<br />

<strong>for</strong> both longitudinal and shear waves?<br />

A. Poisson’s ratio law<br />

B. Snell’s law<br />

C. Fresnel’s field law<br />

D. Charles’ law

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