Cleaning Fibers

[the kid]

We have a pair of fibers that have been causing us issues, various reasons but they also seem to keep getting dirty.

 

Does anyone have a simple and "easy" way to clean fibers or is it always going to be a non inhouse operation ?

[bruce]

Are you talking about cleaning the fibre ends, or the receptacles that they plug in to?

 

In general, I’ve found that a blast with some air duster works most of the time.

 

If it really is dirt on the end, then a dry wipe with a lint-free tissue (lens tissue) can do the job. You can get little kits with lots of little “strips” that are sealed and peel open - but lens tissue is just as effective.

For more serious contamination, you can do a “wet wipe” with lens tissue and a few drops of IPA. Make sure you immediately follow this with a dry wipe - you don’t want the IPA evaporating on the surface.

 

You can also use lint-free swabs, but if you’re using these on receptacles, take great care - it’s easy to push the dirt in, making it harder to remove. Use the air duster first!

 

And it goes without saying - keep the end caps on when the cable is disconnected.

 

The Cisco guide is at http://www.cisco.com/c/en/us/support/docs/optical/synchronous-digital-hierarchy-sdh/51834-cleanfiber2.html#H2-topic6b and contains some useful info.

 

What sort of fibre are you talking about - single mode or multimode?

[the kid]

Fiber ends (male)

 

The fiber is with these ends http://www.gefen.com/kvm/ext-dvi-fm500.jsp?prod_id=8097 so it is a single cable with a split at each end, but the ends are not exactly what I would call "robust" http://www.gefen.com/kvm/dcable.jsp?prod_id=5981 they are protected, it does feel like there should be a better way to cover them until use as well.

[mackerr]

The fiber is with these ends http://www.gefen.com/kvm/ext-dvi-fm500.jsp?prod_id=8097 so it is a single cable with a split at each end, but the ends are not exactly what I would call "robust" http://www.gefen.com/kvm/dcable.jsp?prod_id=5981 they are protected, it does feel like there should be a better way to cover them until use as well.

 

There should be plastic caps that go over the end of the fiber when you disconnect them. Even with caps they will need periodic cleaning. I have found the preloaded mechanical "push type" cleaners to be very effective. You shouldn't have to clean the fiber for each use if they are protected by caps when not in use, but should be cleaned as a first step in troubleshooting as soon as you experience any problem with the fiber. It looks as if the connectors in the Gefen device are multi mode fiber, is tht the fiber type you are using? LC connectors are not very rugged as they were intended to be connected once in a protected environment and left alone. In the rigors of a production environment they need to be treated with care, and probably replaced at some point.

 

Mac

[bruce]

That’s just standard multimode fibre with LC ends. Very common in the data world.

 

Interesting that the unit says it can be used with both multimode and single mode fibre - usually that needs different drivers.

 

Multimode, in general, is much easier to work with (and to clean) than single mode. The larger core diameter (62.5 microns vs 9 microns) means that the “active area” is about 50 times larger, so less sensitive to slight alignment errors. Also, it’s less likely that a single spec of dust will block the entire core.

 

 

Try some compressed air in a can. Then if that doesn’t work, wipe the cable ends. Put a paper pad or notebook on a flat surface, and a sheet of lens tissue on top. Hold the LC connector vertically, and wipe it once across the tissue.

 

Treat the cable well. Always put the end caps back on when disconnected (and the blank plugs into the transmitter/receiver) to keep dust out.

 

And remember not to bend/kink the fibre.

[the kid]

The caps are always on, quite what happens on site I don't know.

 

They went off for cleaning last week turns out the issue they had was in last cleaning they had not connected the inside of the wheel again. Not something I would have thought would happen. HOWEVER they said they were also a touch on the dirty side and having been out of the case 3 times since feb and once was in the warehouse by me I was a touch surprised.

 

 

I will see what happens when they come back but I will try it when we have issues again.

[Javis]

A good fibre cleaning kit I have found invaluable on production, as moving shows in an out of theatres every week means fibres will inevitably get some dirt on them. Cleaning using fibre cleaning solvents on a chemtronics cleaning pad and then using a cassette cleaner on the LC2 provides an effect method.