Inspection and cleaning techniques for MPO/MTP connector

Inspection and cleaning techniques for MPO/MTP connector

In a quest to achieve a flawless and omniscient optical fiber network, the makers have invented connectors which they fondly call ‘better mousetraps’. These connectors are found useful in achieving cost-effective expansions, in solving certain networking problems and also providing secured terminations to optical fiber cables. Most prominent players in the optical fiber networking market such as, Cozlink have introduced more than 100 types of different fiber connectors so far; but very few of them have been able to retain the interest of the buyers. Due to their complementing high speed QSFP+ ports that make attainment of 100G or 400G optical fiber network easier, MPO/MTP connector is seen as more futuristic alternative as compared to all the existing fiber optic connectors.

Why cleaning fiber optic connectors is so essential

Since optical fiber connectors are proving to be a low cost, low maintenance and easily terminable networking solution, it is advisable to keep them functional and free from damage. Regular inspections and cleaning – only these two things are required to sustain the network for longer periods. Moreover, it is worth noticing that 3Ps essential to achieve an efficient optical fiber connection are:

  1. Perfect Alignment of Core
  2. Physical contact
  3. Pristine interface

Of these 3Ps, the first two requirements are not of much concern as the newer designs and better production techniques have made these a bit redundant. So, the focus is entirely on mastering the fiber optic cleaning procedures.

Cleaning MPO MTP fiber connectors is also essential to ensure that all the cables and QSFP+ ports are available and fit to use. While the world is talking about 100G and 400G technology, undue lenience in the maintenance of MPO/MTP connector can bring the system to a stand-still. So, here are some of the inspection methods that are employed to check the status of this fiber optic connector.

How to inspect MPO optical connector

An MPO optical connector can get contaminated with dirt, oil, environmental conditions, people’s touch and other things. This is how a contaminated optical fiber connector looks like.

Source: http://www.china-cable-suppliers.com/wp-content/uploads/2015/11/clean-connector-and-contaminated-connectors.jpg

A probe microscope is one of the most used and very handy inspection tools that can be used to find the cleanliness status of the interface. It is quite useful for detecting dust and oil traces on the connector. An MPO optical connector has to be inspected on both ends – Male (patch cord) and Female (Bulkhead). While patch cord can be inspected easily, the bulkheads are prone to more dirt and are more likely to get ignored. Thus, pay more attention to bulkhead while inspecting the optical fiber connector.

One must observe proactive inspection to avoid any problems in future. Once fit into the system, the optical fiber connector cannot be removed as per the whims and fancies of the inspector. Moreover, if the inspection is done after the occurrence of a problem, the expert may be required to deal with a completely damaged fiber connection.

MPO optical connector cleaning process

Whether to choose wet or dry cleaning procedure depends upon how stubborn the contaminants are.  Dry cleaning is mostly preferred before the mating and must be included in IBYC (inspect before you connect) plan. No matter how clean the interface looks, it must be dry- cleaned to eradicate the possibility of any kind of contamination. Dry cleaning is carried out on the card edge, on the open/unmated cable assemblies and at the backplane. There are certain mechanical fiber optic cleaning tools available that help achieve overall clean connector interface as these are able to reach all these surfaces easily.

Dry cleaning only is certainly not enough for dirt-less connector interface. Wet cleaning fiber optic connectors and patch cables is also recommended when the dust particles are stubborn and are detected even after repeated inspections.

Recommended fiber connector cleaner types

To achieve flawless cleaning, an MPO cleaner is made available in two types – single-click cleaner and a cassette cleaner.

A cassette cleaner is designed to clean different fiber connectors including MPO/MTP ones. This cleaner should be operated in the direction as instructed in the manual. Reverse direction usage may cause contamination again leaving the whole process futile. The connector interface is put into the cassette cleaner as show in the figure below. It can be used to carry out more than 525 cleanings with a single purchase.

Source: http://www.fs.com/blog/wp-content/uploads/2016/11/cassette-cleaner.jpg

One-click cleaner is another handy cleaning tool for MPO/MTP connectors. It works perfectly in the situations when both the adapter and connector demands cleaning. It can carry out about 600 cleans. This cleaner is appreciated a lot because of the convenience and the level of cleanliness it offers.

Source: http://www.fs.com/blog/wp-content/uploads/2016/11/one-click-cleaner.jpg

Some cleaning accessories you may require to keep MTP connector pristine

Both the dry and wet cleaning employs certain accessories such as optical grade dust removers, lint-free wipes, lint-free swabs etc. This is how you can dry clean the MTP connector interface using a swab or wipe:

  1. Start inspection only after ensuring that the lasers are turned off. Ignoring it may expose the eyes to lasers that are harmful for eye health.
  2. Take a resalable container and keep the endcap in it after removing to start the cleaning process.
  3. A fiberscope is used to probe the connector at the adapter or bulkhead region.
  4. The dirty adapter must be cleaned with a lint-free swab that complements the ferrule size correctly.
  5. Check swab properly before inserting it into the adapter.
  6. Pick a direction, say clockwise, and keep rotating the swab in circular motion in this direction.
  7. Discard the swab after use.  Ensure not to reuse the swab.
  8. Repeat the cleaning if it is required.
  9. Always inspect the connector just before plugging it into the adapter, even after the completion of cleaning process.

Source: http://www.cisco.com/c/dam/en/us/support/docs/optical/synchronous-digital-hierarchy-sdh/51834-cleanfiber2-12.gif

Conclusion

Cleaning an MPO/MTP connector is a trickier process because of the complexity of its design. Its multiple fiber structure and a large contact surface make it more prone to dirt and other contaminants. Therefore, a fool-proof method of cleaning and the use of recommended MTP connector cleaning tools only are recommended for better life of these connectors applicable in high speed networks.

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