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Fiber Optics Cleaning Methods

Methods and Steps in Cleaning Fiber Optics

Bare Fiber, Connectors, Adapters

CLEANING

Air - Air cleaning is done without wipes to blow away dust and other
particle contamination. It is sometimes used after drying or dry wipes when
lint has been a problem, even with "lintless" cleaning wipes. Use the
supplied narrow tube nozzle extension and blow at an angle across the
surface you are cleaning and in a direction away from you. Do not tilt or
shake the air can.

Alcohol - Isopropyl alcohol is the most commonly used solvent to loosen
particle contamination and dissolve oils. It is used on wipes, through
sprays, soaks, and ultrasonic cleaning. Use only the highest concentration
available (look for 99% in bottled, and highest in canned or wet wipes).
Replace wipes often. Clean dispensers often. Keep soaks and ultrasonic
baths filled to copacity and covered between uses. Replace and clean
soaks and ultrasonic baths as per the amount of usage - daily in a high use,
assembly or manufacturing environment, less in lab use.

Wipes - Both dry and wet wipes are used in the cleaning process. Wet
wipes are used to loosen and remove contaminants. Dry wipes are used as
a final wipe to remove any residual oils and evaporative water spotting.
Use wipes in a single circular or straight wiping motion. Avoid wiping back
and forth as this returns your surface to an area of the wipe that has
removed contamination. Replace wipes often. Larger wipes may be used
multiple times if a different section of the wipe is used. Remember, single
use where contamination has been removed.

Swabs - Use swabs when cleaning adapters or the face of a connector
through an adapter. When cleaning adapters, a straight single in/out
motion is all that is necessary. Rotating the swab in an adapter is useless as
the floating sleeve will turn with the swab. When cleaning connector end
faces through an adapter, a single rotation after insertion to contact is done.
Do not rotate back and forth as this could cause scratching by returning
removed contamination to the connector surface. Some companies
recommend up to 4 uses of a cleaning swab, but a used or contaminated
swab should not be reused. Remember that connector cleaning is best done
through disassembly and disconnect, rather through the adapter since only
a partial clean can be done and dirt and oils may be trapped in the adapter
area.

Soaking - Sometimes a solvent soak is necessary to loosen particle
contamination or remaining insulation particles after stripping. Only soak
the fiber and not insulation.

Ultrasonic - Ultrasonic cleaning is done often in a manufacturing
environment where consistency is necessary in procedures. It eliminates
the need for handling or touching the fiver or connector. Ultrasonic
cleaners work well for removing remaining insulation from stripping, dust,
dirt, lint fibers, and oils, without the need for contact cleaning with wipes.

DRYING

Open air dry- Not good unless using a fast evaporating solvent, such as a
higher flammability alcohol (like ethyl alcohol) and would not commonly be
used because of increased fire and health hazard.

Pressurized air dry - Best results are obtained when quickly drying the wet
cleaned component to avoid water spotting. Use pre-filtered canned air and
keep upright to avoid any chance of propellant being sprayed.. Remember
that not all canned air is the same and tests should be done to determine
which manufacturer will provide the best for your application.

Wipes - Wipes will be used to dry the component surfaces as a final
operation in the cleaning process. The dry wipe will remove any spotting
and oils that would possibly be left after an alcohol and air clean.

INSPECTION

Hand scopes, video scopes, and microscopes are used for inspection of the
fiber optic surfaces before and after cleaning. When first working on a
cleaning problem, it is good to inspect before to see what the real problem is
so you can use the right cleaning or troubleshooting procedure. For
example, you may be performing the best cleaning procedure possible, but
inspection may reveal a certain type of damage that cleaning will not
remedy.

Some notes on inspection:

- Inspection is not always necessary if your procedure is correct and
consistent or repeatable.

- Eye inspection will find larger contamination, but not small or oil
contamination. A scope is necessary.

- Scope inspection is very time consuming, especially with tens, or even
hundreds of connectors in an installation. Is it necessary in your
application?

- An adapter scope, one with a camera head at the end of a narrow "snake,"
is a good tool, but best cleaning and inspection is done through
disassembly and disconnect if at all possible.

REPOLISH

Repolishing can be performed in cases of damage that resulted from
mishandling or inadequate cleaning over time. This is done only when
scratches, chips, or burns have occured on the connector face fiber core
area. With the proper repolishing, a connector can be restored to new
condition. Repolishing is most often needed in areas with high number of
reconnecting, such as testing, debug, and research and development, since
the chances of contamination and hot plug laser burns are introduced each
time the connector is open.

Some notes on repolishing:

- Repolishing is the last option to restore a signal when a replacement cable
or jumper is not available.

- Repolishing should almost never be necessary with proper care and
handling.

- A properly trained and skilled technician is necessary when repolishing.