I recently watched my coworker disassembling a computer using only one tool. Was it the right tool for the job? Yes and no. It was the tool he had… it worked, however, there exists definitely several tool out there that would have made the job easier! This example is unquestionably one that many fiber optic installers know all too well. As being a gentle reminder, what percentage of you have used your Splicer’s Tool Kit (cable knife/scissors) to remove jacketing or even slit a buffer tube and then use the scissors to hack away at the Kevlar? Did you nick the glass? Did you accidentally cut through the glass and need to start over?
Correctly splicing and terminating Optical Fiber Ribbon Machine requires special tools and techniques. Training is very important and there are numerous excellent sources of training available. Do not mix your electrical tools together with your fiber tools. Utilize the right tool for the task! Being familiar with fiber work will end up increasingly necessary as the value of data transmission speeds, fiber to the home and fiber to the premise deployments continue to increase.
Many factors set fiber installations apart from traditional electrical projects. Fiber optic glass is very fragile; it’s nominal outside diameter is 125um. The slightest scratch, mark or even speck of dirt will change the transmission of light, degrading the signal. Safety factors are important because you work with glass that can sliver in your skin without being seen from the human eye. Transmission grade lasers are incredibly dangerous, and require that protective eyewear is a must. This industry has primarily been dealing with voice and data grade circuits that may tolerate some interruption or slow down of signal. The individual speaking would repeat themselves, or even the data would retransmit. Today our company is dealing with IPTV signals and customers who can not tolerate pixelization, or momentary locking of the picture. All the situations mentioned are cause for the consumer to look for another carrier. Each situation might have been avoided if proper attention was presented to the methods used in planning, installing, and looking after fiber optic cables.
Having said that, why don’t we review basic fiber preparation? Jacket Strippers are employed to remove the 1.6 – 3.0mm PVC outer jacket on simplex and duplex fiber cables. Serrated Kevlar Cutters will cut and trim the kevlar strength member directly beneath the jacket and Buffer Strippers will eliminate the acrylate (buffer) coating from your bare glass. A protective plastic coating is used for the bare fiber after the drawing process, but just before spooling. The most common coating is really a UV-cured acrylate, which can be applied in 2 layers, resulting in a nominal outside diameter of 250um for your coated fiber. The coating is highly engineered, providing protection against physical damage due to environmental elements, such as temperature and humidity extremes, exposure to chemicals, point of stress… etc. while also minimizing optical loss. Without one, the manufacturer would be unable to spool the fiber without having to break it. The 250um-coated fiber is the foundation for a lot of common fiber optic cable constructions. It is often used as is also, especially when additional mechanical or environmental protection is not required, like inside of optical devices or splice closures. For additional physical protection and easy handling, a secondary coating of polyvinyl chloride (PVC) or Hytrel (a thermoplastic elastomer which includes desirable characteristics to use being a secondary buffer) is extruded within the 250um-coated fiber, improving the outside diameter up to 900um. This sort of construction is referred to as ‘tight buffered fiber’. Tight Buffered may be single or multi fiber and they are seen in Premise Networks and indoor applications. Multi-fiber, tight-buffered cables often can be used as intra-building, risers, general building and plenum applications.
‘Loose tube fiber’ usually consists of a bundle of fibers enclosed in a thermoplastic tube known as a buffer tube, which includes an inner diameter which is slightly bigger than the diameter from the fiber. Loose tube fiber features a space for the fibers to expand. In certain climatic conditions, a fiber may expand then shrink repeatedly or it may be in contact with water. Fiber Cables will sometimes have ‘gel’ within this cavity (or space) yet others that are labeled ‘dry block’. You can find many loose tube fibers in Outside Plant Environments. The modular form of Sheathing Line typically holds up to 12 fibers per buffer tube using a maximum per cable fiber count in excess of 200 fibers. Loose-tube cables can be all-dielectric or optionally armored. The armoring can be used to protect the cable from rodents like squirrels or beavers, or from protruding rocks in a buried environment. The modular buffer-tube design also permits easy drop-away from teams of fibers at intermediate points, without disturbing other protected buffer tubes being routed to many other locations. The loose-tube design will help with the identification and administration of fibers inside the system. When protective gel is found, a gel-cleaner including D-Gel will be needed. Each fiber is going to be cleaned with the gel cleaner and 99% alcohol. Clean room wipers (Kim Wipes) are a wonderful choice to use with all the cleaning agent. The fibers inside a loose tube gel filled cable usually have a 250um coating so that they are more fragile compared to a tight-buffered fiber. Standard industry color-coding can also be utilized to identify the buffers as well because the fibers within the buffers.
A ‘Rotary Tool’ or ‘Cable Slitter’ can be utilized to slit a ring around and thru the outer jacketing of ‘loose tube fiber’. As soon as you expose the durable inner buffer tube, you can make use of a ‘Universal Fiber Access Tool’ which is designed for single central buffer tube entry. Used on the same principle because the Mid Span Access Tool, (that enables access to the multicolored buffer coated tight buffered fibers) dual blades will slit the tube lengthwise, exposing the buffer coated fibers. Fiber handling tools such as a spatula or a pick can help the installer to access the fiber needing testing or repair. When the damaged fiber is exposed a hand- stripping tool will be employed to take away the 250um coating in order to work using the bare fiber. The next phase will likely be cleansing the fiber end and preparing so that it is cleaved. A great cleave is among the most essential factors of producing a low loss over a splice or even a termination. A Fiber Optic Cleaver is actually a multipurpose tool that measures distance from your end from the buffer coating towards the point where it will probably be joined and it also precisely cuts the glass. Always remember to utilize a fiber trash-can for your scraps of glass cleaved from the fiber cable.
When performing fusion splicing you will need a Fusion Splicer, fusion splice protection sleeves, and isopropyl alcohol and stripping tools. If you use a mechanical splice, you will want stripping tools, mechanical splices, isopropyl alcohol along with a mechanical splice assembly tool. When hand terminating a fiber you will want 99% isopropyl alcohol, epoxy/adhesive, a syringe and needle, polishing (lapping) film, a polishing pad, a polishing puck, a crimp tool, stripping tools, fiber optic connectors ( or splice on connectors) and piano wire.
When a termination is finished you need to inspect the final face in the connector with Optical Fiber Proof-Testing Machine. Being sure that light is becoming through either the splice or perhaps the connection, a Visual Fault Locator can be applied. This piece of equipment will shoot a visible laser down the fiber cable so you can tell that there are no breaks or faulty splices. If the rhnnol light stops down the fiber somewhere, there is probably a break inside the glass at that point. When there is more than a dull light showing in the connector point, the termination had not been successful. The light should also go through the fusion splice, if this fails to, stop and re- splice or re-terminate.