Fiber optic cleaning is one of the most important thing in the process of fiber optic system maintenance, which is required to keep quality connections between fiber optic equipment. As we know, the fiber optic connector consists of fiber optic plug and the adapter. The ends of the fiber optic cables are held in the core of ferrule in the plug. Keeping the fiber end face and ferrule absolutely clean is very essential, since any particles such as dust, oil or lint on the end face of the fiber, it will disrupt the light transmission trough the fiber and lead to the completeness of optical signals for the component or the entire system.
For proper performance of the SC fiber optic cable, you must keep the SC connector clean and free of dust. Small micro-deposit of oil and dust in the canal of the connector could cause loss of light, reducing signal power and possible causing intermittent problems with the optical connections. Below picture show the part of the end face of an unclean and clean ferrule of SC connectors.
What should be followed before the fiber optic cleaning
1.Before cleaning the fiber optic connectors, make sure to disconnect the fiber optic cables from both ends and then turn off any laser source.
2. Do not allow the end of the fiber optic cable to make contact with any surface including your fingers.
3.Never to bend the fiber cable, which will in turn cause internal breaks along the fiber and cause poor performance or instability.
4.Use the finger cots or powder free surgical gloves to handle the fiber optic cables.
5.Use fresh spectroscopic grade Methanol or Isopropyl Alcohol as the only cleaning solvent.
6. In the daily connection work, a connector housing should be used when plugging or unplugging a fiber. A protective cap should be used to cover the unplugged fiber connectors.
7. In the process of the fiber optic cleaning, the end face of the connector should never be touched and also the clean area of a tissue of swab should not be touched or reused.
Cleaning Procedure
At the beginning of cleaning job, a fiber microscope should be used to inspect the fiber end, if it is contaminated as either images shows below, it should be cleaned with the dry cleaning method.
1.Blow the fiber surface with a stream of Clean Dry Air (the so called CDA), which will dislodge larger, loose particles. Keep in mind, don’t tip the can of the CDA while blowing. Because the liquid may be released contaminant on the surface of the fiber.
2.Place 1-3 drops of spectroscopic grade methanol or isopropyl alcohol in the center of a lens tissue. Do not use Acetone as a cleaning solvent on the fiber optical surfaces. Besides, to ensure the purity of the methanol or alcohol, you should never insert the lens tissue or swabs into the liguid.
3.Hold the fiber by the connector. Place the wet portion of the lens tissue on the optical surface and slowly drag it across. At this step, don’t use lens paper to dry it because the dry lens paper is extremely abrasive.
4.Examine the surface of the fiber under high density light using a magnifier, an optical loop, or a video inspection tool. If streaks or contaminants still remain, repeat the process using a fresh lens tissue.
5.Immediately install a protective cover over the end of the cable to avoid re-contamination or insert the fiber for immediate use.
