NDT Visual Testing Fundamentals 3

Question 1

A visual testing procedure requires 20/40 near vision acuity. What does this specification mean?

Accepted Answer

The inspector must see at 20 feet what a normal eye sees at 40 feet

Answer

20/40 vision means the inspector sees at 20 feet what a person with normal vision sees at 40 feet, indicating reduced acuity.

Question 2

What is the primary purpose of a comparator (replica tape) in visual testing?

Accepted Answer

To transfer and preserve a 3D impression of a surface for measurement

Answer

Replica tape (such as Testex Press-O-Film) creates a physical impression of a surface profile that can be removed and measured with a micrometer.

Question 3

When using a flexible video borescope, image distortion at the edges of the field of view is typically caused by:

Accepted Answer

Wide-angle lens geometric distortion

Answer

Wide-angle lenses used in borescopes introduce barrel or pincushion distortion, especially at field edges, which can affect dimensional assessments.

Question 4

According to SNT-TC-1A, which level of VT certification has the primary responsibility for interpreting and evaluating test results?

Accepted Answer

Level II

Answer

SNT-TC-1A Level II personnel are qualified to set up, calibrate, conduct, and interpret/evaluate VT results.

Question 5

Which condition would MOST adversely affect a visual inspector's ability to detect color-contrast discontinuities?

Accepted Answer

Red-green color vision deficiency

Answer

Red-green color deficiency impairs the ability to distinguish contrast between certain colors, which can mask discontinuities highlighted by color-contrast methods.

NDT - Non-Destructive Testing Practice Test

NDT - Non-Destructive Testing Practice Test

NDT Visual Testing Fundamentals 3