Which instrument is commonly used to visually inspect internal bore surfaces?

Which instrument is commonly used to visually inspect internal bore surfaces?

• A. Magnifying glass
• B. Phototube
• C. Microscope
• D. Borescope

Answer: (D)

Inspecting the inside of a bore requires a tool that can enter the opening, illuminate the surface, and relay a view of areas you can’t see from the outside. A borescope is designed for this purpose: it’s a long optical tube (rigid or flexible) with a light source and viewing capability that can be inserted into holes, conduits, or bores to inspect interior surfaces for wear, scoring, corrosion, or defects. Some borescopes include a camera, so you can see and even record the image. The other options don’t fit this use. A magnifying glass works only on external surfaces and can’t reach inside a bore. A phototube is a light-detection device, not an inspection instrument for viewing interior surfaces. A microscope provides high magnification for small samples on a stand and isn’t designed to access internal bore areas.

Inspecting the inside of a bore requires a tool that can enter the opening, illuminate the surface, and relay a view of areas you can’t see from the outside. A borescope is designed for this purpose: it’s a long optical tube (rigid or flexible) with a light source and viewing capability that can be inserted into holes, conduits, or bores to inspect interior surfaces for wear, scoring, corrosion, or defects. Some borescopes include a camera, so you can see and even record the image.

The other options don’t fit this use. A magnifying glass works only on external surfaces and can’t reach inside a bore. A phototube is a light-detection device, not an inspection instrument for viewing interior surfaces. A microscope provides high magnification for small samples on a stand and isn’t designed to access internal bore areas.