Maintaining clean fiber connections is a vital part of any network installation, but proper cleaning is often overlooked. Check out the 5 facts below, and then make sure you think twice before making a connection without ensuring that your connector’s end faces are clean:

Why should I clean and inspect fiber connections before installation?

1: Improper cleaning is the number one cause of network failures and contractor call-backs. In fact, USCONEC indicates that 80% of network owners and 98% of cable installers cite contamination as the root cause of network failures. The use of dry cleaning tapes is recommended for single and multi-fiber ferrule connectors. Dry cleaning tape sticks and swabs, used with nonvolatile optical cleaning fluids, are acceptable for cleaning optical ports. Note that this recommendation does not include expanded beam lens (EBL) connectors or other connectors that may have anti-reflection coatings that require other special cleaning techniques.

2: Your fiber isn’t clean, even if it appears to be with a naked eye. A dust particle, as small as one micrometer, can block up to one percent of the transmitted light through the connector. A speck of dust as small as nine micrometers is still too small to see without a microscope, but it can completely block the fiber’s core. Use a fiber optic microscope with a good connector optical stage capable of 200X magnification for multimode connectors and 400X for single-mode connectors. Digitally record your photos for future reference on the link.

3: It’s nearly impossible to prevent contamination, even with the dust caps that come installed on your cords and connectors. Common sources of contamination include oils and dust, packaging material and other worksite debris. Wet reagent-grade isopropyl alcohol can be used for more stubborn contaminates on the ferrule surfaces if necessary (see the table below). With Legrand’s strict manufacturing processes, cable assemblies may be clean right out of the bag, but we still recommend that you always clean and inspect the ferrules before plugging in.


4: Contamination prevents proper physical contact and causes defects that cause permanent damage to your fiber. 

PC, UPC and APC connectors rely on proper physical contact to achieve a low loss, low reflection optical connection. If there is a film or debris that causes an air gap on the ferrule surface, the insertion loss of the connector increases, and so do the reflections.


5: Charged dust particles attract more particles. Because glass fibers are insulators, contaminated connector end faces will also continue to attract and accumulate more and more dust and debris. A clean fiber optic connector will appear pristine under the microscope and there will be no contaminants on the fiber’s surface or damage to the core.

How should I clean and inspect connectors on cassettes?

Not only must the patch cord fiber connectors and the ports they connect to be clean, but those same connectors should be cleaned and checked on optical cassettes, splitters, and conversion modules. Here is a flowchart that is useful for the proper cleaning procedure on your fiber optic cassette modules:


So… Make sure you know the correct connector to plug into any optical port before plugging it in.

Make sure to clean and inspect your fiber connectors and optical ports with the proper cleaning tools beforehand, and don’t use any assemblies that are damaged.

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This article was originally posted here.