Fiber Optic Cable Tester - What Is It and How to Use?
What is a fiber optic cable tester?
A fiber optic cable tester is a hand-held troubleshooting device that sends red light
from a semiconductor laser (635nm) down a fiber to check for faults such as cracked fibers
or defective splices.
The visible red light travels along the fibre core until it reaches a fault, where it
leaks out of the fiber. Light leaking through the fault can be seen through plastic coatings
and jackets under suitable illumination. Infrared light in the signal leaks out at the same
point, but your eyes cannot see it. The tester emits Class II red laser beam, making the light
escaping from the damaged fiber easily visible from a distance.
Attenuation of glass fibres is much higher at 630 to 670nm wavelengths of red light than
in the 1300 to 1650nm transmission window, but the red light can still travel up to 5km through
standard fibers. Note that the fibers must be exposed to use fiber optic cable tester effectively.
If the red light leaks out inside a thick cable wrapped in black plastic, you can't see it.
This technique is particularly valuable in equipment bays and other places inside buildings
where fibres are exposed.
Shining a flashlight beam down a multimode fiber can serve the same function, and has
long been used to trace fiber continuity as well. However, the flashlight couples little light
into a single mode fiber.
Whether installing or troubleshooting, the fiber optic cable tester is an essential tool
that quickly and easily locates problem areas in fiber cables. By pinpointing the exact location
of fiber damage, technicians can diagnose, troubleshoot, and fix the problem effectively. The
cable tester is also used for conducting continuity tests and performing fibre identification.
The Continuous⁄Flash control button lets operators choose between continuous or flashing illumination.
Fiber optic cable tester can be used to locate sharp bends, breaks, and damages in fibre.
It can also conduct end-to-end continuity tests. The other function is to perform fibre tracing
What types of tester are available?
There are two unique versions of fiber cable tester that are ergonomically designed for
comfortable handling and portability. Both versions are equipped with a 2.5mm interface and
are compatible with connectors such as SC, ST, and FC, while the 1.25mm adapter enables connection
to LC and MU connectors. To ensure ruggedness, it features rubber seals, a fully enclosed
laser head and a long-lasting On⁄Off switch. It has been tested to provide reliable
operation under intensive use and harsh conditions.
Colin Yao is an expert on fiber optic communication technology and products. Learn more
about fiber optic cable tester and
on Fiber Optics For Sale Co. web site.
More Network Troubleshooting and Support Articles:
• Putting Your SME Data on the Internet
• How to Design a Highly Reliable Fiber Optic Network
• Nine Tips for Designing a Small Business Network
• What is Structured Cabling for LANs (Local Area Networks)?
• Creating a Backup Plan
• Website Design Process Client Meeting Checklist
• VPN and VPN Protocols
• Brainstorming to Collect Data in Designing the Corporate Computer Network
• Built-in Utilities for Network Troubleshooting
• Letting Your SME Users Access the Internet