CFOT Fiber Optic Cleaning and Inspection 3

Question 1

What does the industry best practice principle 'inspect before you connect' require?

Accepted Answer

Visually inspect every connector end-face for contamination before mating

Answer

Inspecting every end-face before mating is a mandatory step that catches contamination which could cause signal loss or permanent damage if connectors were mated without inspection.

Question 2

Why must technicians never look directly into the end of an active fiber optic cable or connector?

Accepted Answer

Infrared laser light can cause permanent eye damage with no visible warning

Answer

Fiber optic systems use 850 nm, 1310 nm, or 1550 nm infrared lasers that are invisible yet powerful enough to permanently damage retinal cells without any sensation of pain.

Question 3

What does a reel-type cassette cleaner use to clean fiber optic connector end-faces?

Accepted Answer

Pre-moistened and dry cleaning fabric that advances to a fresh section each use

Answer

Cassette cleaners use a reel of cleaning fabric that automatically advances to a fresh section with each use, providing reliable wet-then-dry cleaning in a single stroke.

Question 4

What end-face geometry parameters measured by an interferometer directly affect connector return loss performance?

Accepted Answer

Fiber height (protrusion or undercut) and radius of curvature

Answer

Interferometers measure fiber protrusion/undercut and radius of curvature to verify proper physical contact geometry, which determines how well end-faces mate and their return loss performance.

Question 5

When inspecting a fiber end-face under a microscope, what appearance distinguishes a scratch from surface contamination?

Accepted Answer

Scratches appear as linear marks that persist after thorough cleaning attempts

Answer

Scratches are physical damage to the glass and appear as persistent linear marks that cannot be removed by any cleaning method, unlike contamination which is removed by cleaning.

CFOT - Certified Fiber Optic Technician Practice Test

CFOT - Certified Fiber Optic Technician Practice Test

CFOT Fiber Optic Cleaning and Inspection 3