Define borescope and its use in VT.

• A. A slender viewing instrument with an eyepiece or camera used to inspect interiors or hard-to-reach surfaces; provides line-of-sight images for VT.
• B. A device for measuring surface roughness.
• C. A software program to simulate VT.
• D. A type of coating to prevent corrosion.

Answer: (D)

A borescope is a slender viewing instrument with an eyepiece or camera that lets you inspect interiors or surfaces that are hard to reach. In visual testing, it provides a line-of-sight image of concealed areas, enabling inspection of inside engines, turbines, pipelines, and other cavities without disassembly. It can be rigid or flexible, often uses fiber optics or a small video camera, and is equipped with illumination and sometimes an articulating tip to view different angles. This makes it essential for checking for flaws such as cracks, corrosion, wear, or misalignment in places you can’t see directly, and for documenting findings with pictures or video for records and evaluations. The other options describe different tools or purposes—measuring surface roughness, software simulation, or coatings—not the instrument used to directly view internal or hidden regions.