Fiber Optic Testing

By: CableOrganizer®

When you’re installing a fiber optic network, one of the most important steps in the operation is testing the newly installed and terminated optical fiber cables, to be sure they’re functioning properly. Before the testing and certification of a fiber network can begin, there are a couple of points you’ll need to have covered, to ensure that the job is accurately and successfully completed:

  • • Be well acquainted with the components and configuration of the network you’ll be testing.
  • • Determine which tools and testing equipment you’ll need for the job, knowing exactly how to use them before you arrive at the test site.

There are two basic categories in which typical fiber optic cables are tested: Continuity, and End-to-End Optical Loss.



Because a broken fiber within a cable means interrupted data transmission, it’s very important to evaluate the continuity of cables, in order to find out whether or not any fibers have signal-inhibiting flaws.

In Continuity tests, a pocket-sized, light emitting instrument known as a fiber optic tracer or visual fault locator, is attached to each cable’s fiber optic connector. It sends light signals into one end of the cable. If the light is detectable at the other end of the cable, that’s an indication the fiber has no breaks in it — and it is fit for use. On the other hand, if the far end of the cable is not visibly lit, that’s a sign that a break or some other imperfection in the fiber is preventing it from transmitting signals.


Cables aren’t the only fiber optic network components to be checked for their transmission ability: connectors are put to the test as well. Installers are able to inspect fiber optic connectors with special microscopes, making sure that they are smoothly polished and able to provide an effective connection.


optical loss

Optical loss testing enters the equation when it comes time to measure the difference between the starting amount of optical power that is sent into a cable’s transmitting end — and the amount that makes it to the receiving end. In order to evaluate Optical Loss, three types of test equipment are needed: a power meter, a test source and a reference cable or two.

When measuring end-to-end optical loss, the installation technician begins by connecting the cable being tested to a reference cable. Next, a test source is used to send a light signal into the transmitting end of the test cable. The amount of optical power that reaches the far end of the attached reference cable is measured with a power meter. This measurement gives the optical loss — or amount of power lost during end-to-end transmission — of the tested cable.

Whether you’re installing network cables or testing them, visit CableOrganizer® and check out our incredible inventory of fiber optic supplies. From optical fiber cables by Corning to testers from Kingfisher, we have everything you need to get your fiber optic job done!

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