ASNT Ultrasonic Testing - Level I & II Practice Questions — 10 Free (2026)

A wall read 12.0 mm four years ago and reads 10.0 mm now. What is the loss rate?

• A. 0.2 mm per year
• B. 0.5 mm per year ✓
• C. 1.0 mm per year
• D. 2.0 mm per year
• E. 4.0 mm per year

The wall lost 2.0 mm over four years, so the rate is 2.0 divided by 4, or 0.5 mm per year. That rate is what a remaining life assessment is built on. ASTM E797 thickness measurement

A 2 MHz probe is used on steel where the longitudinal velocity is 5900 m/s. What is the wavelength?

• A. 1.48 mm
• B. 2.36 mm
• C. 2.95 mm ✓
• D. 3.93 mm
• E. 5.90 mm

Wavelength is velocity divided by frequency: 5900 m/s divided by 2,000,000 Hz is 0.00295 m, or 2.95 mm. It sets the smallest feature the beam can usefully separate. ISO 16810 ultrasonic testing general principles

How do most weld acceptance criteria treat an indication?

• A. By its amplitude and its length together ✓
• B. By the depth at which it lies within the thickness of the joint examined
• C. By amplitude alone
• D. By the probe angle
• E. By the gain

A short indication is tolerated at a height that a long one is not, which is why both figures have to be measured before a decision. ISO 11666 acceptance levels for ultrasonic testing of welds

What is a gate on an ultrasonic instrument?

• A. The reject control
• B. The control that sets how much of the transmitted energy enters the part
• C. A filter
• D. A physical cover
• E. A selected part of the time base watched for signals ✓

Anything crossing the threshold inside that window can raise an alarm or be recorded, which is what makes automated scanning possible. ASTM E317 evaluating ultrasonic instrument performance

What does a counterbore in a pipe weld produce on the screen?

• A. A surface wave
• B. No signal at all
• C. A geometric echo near the root position ✓
• D. A rise in the noise level across the whole of the displayed time base
• E. A back wall echo

It appears on every joint machined the same way, and knowing the joint detail is what stops it being reported each time. ISO 17640 ultrasonic testing of welds

How is the probe index point established?

• A. By marking the centre of the crystal on the side of the probe with a rule
• B. It is given by the maker
• C. By measuring the wedge
• D. From the curved surface of a calibration block ✓
• E. From the probe's nominal angle printed on the label

The radius returns the strongest echo when the beam leaves from the point aimed at its centre, and the mark on the block gives the position. ISO 2400 calibration block number 1

Why is grey cast iron rarely examined by conventional ultrasonics?

• A. Its acoustic impedance is too close to that of water
• B. The velocity is too high
• C. Its surface is always too rough for a contact probe
• D. The graphite flakes scatter the beam severely ✓
• E. It does not transmit longitudinal waves at all

Attenuation is so high that little energy reaches any depth, and what returns is dominated by the structure rather than by any flaw. ASNT Study Guide UT Level II, acoustic properties

Why does a flaw give a lower echo when it is unfavourably oriented?

• A. Because it is smaller
• B. Because the beam loses energy in the metal before it reaches such a flaw
• C. Because the beam is attenuated more at oblique incidence
• D. Because the reflected energy is sent away from the probe ✓
• E. Because the flaw converts the incident energy into heat

This is why amplitude alone is a poor guide to size and why more than one angle is used on a joint that matters. ASTM E587 angle beam contact testing

Why is the refracted angle verified rather than taken from the probe label?

• A. Because the angle changes with the gain setting used during the examination
• B. Because wedge wear and the material both change it ✓
• C. Because the label is only accurate for aluminium
• D. Because the label gives the incident angle, not the refracted one
• E. Because the angle changes with the couplant used

A beam two degrees from where it is believed to be misses the root or reports a reflector at the wrong depth, and neither is visible on the screen. ASTM E587 angle beam contact testing

Why is a nickel alloy weld difficult to examine?

• A. Its velocity is identical to the parent metal
• B. The weld metal absorbs the couplant
• C. Because nickel alloys transmit sound only at frequencies below one megahertz
• D. It is too hard for a probe to couple to
• E. Coarse dendritic structure scatters and deflects the beam ✓

It behaves much as an austenitic weld does, and the same remedies of lower frequency and longitudinal angle probes are used. ISO 17640 ultrasonic testing of welds