NDT Nondestructive Testing Methods & Techniques 3

Question 1

What NDT method uses high-frequency sound waves transmitted through a couplant to detect internal flaws?

Accepted Answer

Ultrasonic testing

Answer

Eddy current testing

Answer

Acoustic emission testing

Answer

Infrared thermography

Question 2

During a hydrostatic pressure test, what is the primary hazard compared to a pneumatic pressure test?

Accepted Answer

Pneumatic tests are more dangerous because compressed gas stores significantly more energy than liquid

Answer

Hydrostatic tests use a compressible fluid, storing more energy

Answer

Hydrostatic tests are more dangerous because water is heavier

Answer

Both tests present identical hazards

Question 3

In eddy current testing, what effect does a crack or void in a conductive material have on the eddy current flow?

Accepted Answer

It forces eddy currents to flow around the discontinuity, changing the impedance signal

Answer

It increases the eddy current amplitude uniformly

Answer

It eliminates all eddy currents in the test material

Answer

It has no measurable effect on eddy current flow

Question 4

Which document typically establishes the specific acceptance criteria that a boilermaker NDT inspector must apply when evaluating weld indications?

Accepted Answer

The applicable construction or inspection code (e.g., ASME Section VIII)

Answer

The NDT equipment manufacturer's operating manual

Answer

The local fire marshal's inspection report

Answer

The OSHA 29 CFR 1910 general industry standard

Question 5

What is 'signal-to-noise ratio' in the context of ultrasonic testing?

Accepted Answer

The ratio of the flaw signal amplitude to the background noise level

Answer

The ratio of the probe frequency to the material thickness

Answer

The ratio of compression wave velocity to shear wave velocity

Answer

The ratio of the instrument gain to the couplant viscosity

Question 6

When performing liquid penetrant testing on a rough, as-welded surface, what precaution is most important?

Accepted Answer

Ensure thorough pre-cleaning to remove weld spatter and contaminants from the surface

Answer

Use a shorter penetrant dwell time to avoid over-penetration

Answer

Apply developer immediately without a dwell period

Answer

Use only solvent-removable penetrant on rough surfaces

Question 7

In magnetic particle testing, the 'circular magnetization' technique is best suited to detect:

Accepted Answer

Longitudinal (lengthwise) discontinuities parallel to the current flow

Answer

Transverse (crosswise) discontinuities perpendicular to the length of the part

Answer

Subsurface laminations deeper than 0.5 inches

Answer

Corrosion pitting on internal surfaces