Handling cables and patchcords is a major source of damage and performance degradation in systems. Let’s examine your understanding of how to care for them during installation, testing and moves/adds/changes. Correct answers and explanations are in red.
1. The biggest cause of problems with fiber optic cables is _________.
Dirty connectors which causes optical loss and may potentially damage the connectors is the biggest cause of problems with fiber optic cables.
2. Airborne particles of dirt are about the size of _________.
A. A human hair
B. The core of single-mode fiber
C. The diameter of the fiber
D. The diameter of the connector
Typical airborne dirt particles are about the size of the core or singlemode fiber.
3. Besides causing attenuation, dirt particles can cause scratches on the polished fiber ends.
Dirt particles are often hard silica and can scratch polished fiber ends.
4. The cleanliness of a fiber optic connector should be checked with a(n) _________.
A. Visual tracer or fault locator
B. Optical loss test set
C. Optical time-domain reflectometer
D. Fiber optic inspection microscope
Microscopes are used to inspect the connector ferrule tips under high magnification to find dirt and scratches.
5. The ends of fiber optic connector ferrules should be cleaned with special cleaning pads or _________.
A. Cotton swabs saturated with medical alcohol
B. Lint-free wipes moistened with pure isopropyl alcohol
C. Clean tissues
D. You can blow on them and wipe them on your shirt
Cleaning pads must be lint-free and highly pure isopropyl alcohol (99% pure) to prevent leaving residue on the end of the connector ferrule.
6. Bulkheads or fiber optic mating adapters should be cleaned with _________.
A. Canned air
B. Clean connector ferrule
C. Compressed air
D. Special cleaning swabs or lint-free swabs and alcohol
The only good way to clean inside mating adapters is to use a fitted lint-free swab moistened with alcohol or a special dry swab made for that purpose.
7. When fiber optic connectors are not in use, the tips of the ferrules should be covered with dust caps to _________.
A. Keep the ferrules from getting dusty
B. Prevent damage to the ends of the ferrules if dropped
C. Prevent dirty fingers from touching the ends of the ferrules
D. All of the above
Dust caps on fiber optic connectors protect them in all these ways.
8. All patchcords, either copper or fiber, can be damaged by cable ties that are cinched too tightly.
Cable ties can cause attenuation in fiber optic cables and return loss problems in copper cables.
9. When arranging copper or fiber patchcords around patch panels, care must be taken to _________.
A. Keep fiber and copper cables separated by at least 6 inches (150 mm)
B. Not exceed the appropriate cable bend radius
C. Keep color-coded cables together
D. Bundle and secure cables tightly with cable ties
Around patch panels, care must be taken to ensure patchcords are not bent too tightly as they are routed between connections.
10. Cables used as reference cables with test equipment _________.
A. Can be any cable found on the job site
B. Must always be supplied new by the tester manufacturer
C. Should be tested regularly to ensure they are in good condition
D. Should be replaced for every job
Cables used with test equipment are connected/disconnected many times and flexed continuously in use causing potential problems. Bad test cables will results in bad test results, a very bad situation for the installer.
HAYES is a VDV writer and educator and the president of The Fiber Optic Association. Find him at www.jimhayes.com.