What's Your Method for Testing Fiber without Terminating It?

There's times when you need to test fiber without terminating the end. A good example is to test the fiber on the drum, or to prove that dark fiber is operational. One method is to use the Corning Cam mechanical splice installation tool.

To test using the Corning Cam mechanical splice tool, strip and cleave a pigtail, feed the cleaned fiber into one end of the Cam splice until it bows (droops). Strip, cleave and clean the tested fiber and insert into the opposite end of the mechanical splice until it droops. Close the levers on the installation tool. Clean and connect your pigtail to the OTDR. Shoot your trace. Once completed, remove the test fiber, while leaving the pigtail installed. Strip, cleave and clean your next fiber.

The best method is Mechanical Splicing; Mechanical splices are most popular for fast, temporary restoration or for splicing multimode fibers in a premises installation. They are also used - without crimping the fibers - as temporary splices for testing bare fibers with OTDRs or OLTSs.

Prepare the cables to be spliced

Strip jacket, removing an adequate amount of jacket, usually 2-3 m, for splicing and dressing the buffer tubes and fibers in the splice closure. Leave the proper amount of strength members to attach the cable to the closure. Refer to the splice closure directions for lengths needed. Clean all water-blocking materials using appropriate cleaners.

Remove buffer tubes exposing fibers for splicing. Generally splice closures will require ~1 m buffer tubes inside the closure to and ~ 1 m fiber inside the splice tray. Clean all water-blocking materials.

Prepare the fibers to be spliced

The process is the same for all splice types: strip, clean & cleave. Each fiber must be cleaned thoroughly before stripping for splicing. When ready to splice a fiber, strip off the buffer coating(s) to expose the proper length of bare fiber. Clean the fiber with appropriate wipes. Cleave the fiber using the process appropriate to the fiber cleavers being used.

Making the Mechanical Splice

Insert the first fiber into the mechanical splice. Most splices are designed to limit the depth of the fiber insertion by the buffer coating on the fiber. Clamp the fiber in place if fibers are held separately. Repeat these steps for the second fiber.

Optimizing Splices Using a Fiber Optic Laser Pen

You can sometimes improve the loss of a mechanical splice by gently withdrawing one of the fibers a slight amount, rotating it slightly and reinserting it. It works best with a VFL (visual fault locator) if the fiber ends that are being spliced are visible.

Testing

Splices can be used to create long cable lengths by splicing multiple cable segments. After splicing, the only way to test it is with an OTDR. Since OTDRs have directional errors, testing may be required from both directions and averaged. Generally long concatenated cables are tested with an OTDR and traces kept for documentation in case of restoration. Be aware of the OTDR distance resolution as a limitation of testing short premises cables.

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