Fiber Optic Testing - Steps by Step
Fiber optic cables are the high-speed wires of glass or plastic that is generally used for communication purposes. These days, many large networks of universities, campuses, corporate and government sectors rely on this fast communication media.
One interesting factor of fiber cables is that instead of using electrical signals they use light signals (because speed of light signals travels faster than electrical signals) carry data from one remote location to another. These cables are easily vulnerable through dust, dirt, oil from body, and from other contamination factors that can limit their ability to transfer signals correctly, so need to be tested after regular intervals. Lets' have a little understanding of how a fiber optic test is performed:
Every cable test goes through a three-step approach, visual inspection, loss testing, and network testing, by the use of special tools and equipment. A fiber optic test is performed using various types of fiber optic test equipment like optical loss test, source and power meter, a microscope adaptor, tracer or visual fault locator, a test cable reference, cleaning solutions, an optical time-domain reflector (OTDR), launch cable etc. In the next segment we will understand how to use these tools in order to perform, a successful fiber optic test.
Visual Testing:
Also known as connector testing, visual inspection is performed to check the breakage of fiber cables. With the help of a fiber optic tracer or fault locator, fiber cable from one end to another is traced to ensure that it is not broken.
To perform this test, one end fiber cable is attached to the visual fault locator. Now, look at the another end, if you can view the light at the other end, then the fiber is not broken, otherwise, re-check connection to find the bad segments on the fiber.
Connect pair of fiber cables at patch panels. Be ensuring that correct two wires are attached to the transmitter (visual tracer) and receiver (an eye here).
High powered fiber optic tracer is used to find the bad sections or the areas of fault on the cable. If tracer results with a red laser light, it indicates that there is breakage on fibers or high loss connectors. Recognize mechanical joins, or pre-polished joint fiber optic connectors, to confirm a high a proper working cable.
A microscope with a medium magnification is used to view cable connectors to ensure that connectors are free of scratches, polished, and smooth without cracks or chips.
Using cleansing solutions and soft cloth wipes connectors carefully.
Determine the power level for loss measurement by turning on the power meter and reset the required wavelength for loss test.
Now connect the cable to the meter and analyze the results.
Loss Test:
Make use of fiber optic testing equipment like sources and power meters in order to measure the loss of optical fiber. For this purpose, source and meter works as a transmitter and receiver over a transmission link.
Join the test cable to the jumper cable and measure the power. Single-ended loss makes use of only the jumper cable while double ended-loss makes use of receives cable connected to the power meter.
Networking Test:
Use a long jumper cable to allow OTDR which confirms loss of joins on outside plant fibers.
Begin with optical time-domain reflector with the shortest pulse width for a cable that is two times larger than cable you test. Trace and determine the ways to improve results.