Recently i watched my coworker disassembling a pc 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 is definitely more than one tool out there that would have made the task easier! This example is certainly 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 make use of the scissors to hack away at the Kevlar? Did you nick the glass? Did you accidentally cut through the glass and have to start over?
Correctly splicing and terminating Fiber Drawing Machine requires special tools and techniques. Training is important and there are numerous excellent sources of training available. Usually do not mix your electrical tools together with your fiber tools. Make use of the right tool for the job! Being familiar with fiber work can become increasingly necessary as the importance of data transmission speeds, fiber towards the home and fiber to the premise deployments still increase.
Many factors set fiber installations apart from traditional electrical projects. Fiber optic glass is extremely fragile; it’s nominal outside diameter is 125um. The slightest scratch, mark or even speck of dirt will impact the transmission of light, degrading the signal. Safety factors important because you are working with glass that can sliver into 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 coping with voice and data grade circuits that may tolerate some interruption or slow down of signal. The individual speaking would repeat themselves, or the data would retransmit. Today we have been working with IPTV signals and customers that will not tolerate pixelization, or momentary locking in the picture. All of the situations mentioned are cause for the client to search for another carrier. Each situation might have been avoided if proper attention was presented to the strategies used when preparing, installing, and maintaining fiber optic cables.
With that being said, why don’t we review basic fiber preparation? Jacket Strippers are utilized to take away 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 the bare glass. A protective plastic coating is applied to the bare fiber following the drawing process, but just before spooling. The most typical 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 caused by environmental elements, including temperature and humidity extremes, being exposed to chemicals, point of stress… etc. while minimizing optical loss. Without one, the producer would struggle to spool the fiber without having to break it. The 250um-coated fiber is the building block for a lot of common fiber optic cable constructions. It is usually used as it is, specially when additional mechanical or environmental protection is not required, including within optical devices or splice closures. For extra physical protection and easy handling, a secondary coating of polyvinyl chloride (PVC) or Hytrel (a thermoplastic elastomer that has desirable characteristics to use being a secondary buffer) is extruded on the 250um-coated fiber, increasing the outside diameter up to 900um. This sort of construction is known as ‘tight buffered fiber’. Tight Buffered may be single or multi fiber and they are observed in Premise Networks and indoor applications. Multi-fiber, tight-buffered cables often are used for intra-building, risers, general building and plenum applications.
‘Loose tube fiber’ usually includes a bundle of fibers enclosed in a thermoplastic tube referred to as a buffer tube, which includes an inner diameter that is certainly slightly larger than the diameter from the fiber. Loose tube fiber features a space for that fibers to expand. In certain climate conditions, a fiber may expand and then shrink again and again or it may be subjected to water. Fiber Cables will sometimes have ‘gel’ in this particular cavity (or space) yet others which are labeled ‘dry block’. You can find many loose tube fibers in Outside Plant Environments. The modular design of Secondary Coating Line typically holds approximately 12 fibers per buffer tube using a maximum per cable fiber count of over 200 fibers. Loose-tube cables can be all-dielectric or optionally armored. The armoring is utilized to protect the cable from rodents including squirrels or beavers, or from protruding rocks in a buried environment. The modular buffer-tube design also permits easy drop-away from groups of fibers at intermediate points, without upsetting other protected buffer tubes being routed with other locations. The loose-tube design will help with the identification and administration of fibers in the system. When protective gel is found, a gel-cleaner including D-Gel will likely be needed. Each fiber is going to be cleaned with all the gel cleaner and 99% alcohol. Clean room wipers (Kim Wipes) are a good choice to use with the cleaning agent. The fibers in a loose tube gel filled cable normally have a 250um coating therefore they are more fragile when compared to a tight-buffered fiber. Standard industry color-coding is also used to identify the buffers as well as the fibers within the buffers.
A ‘Rotary Tool’ or ‘Cable Slitter’ can be employed to slit a ring around and thru the outer jacketing of ‘loose tube fiber’. When you expose the durable inner buffer tube, you can make use of a ‘Universal Fiber Access Tool’ which is made for single central buffer tube entry. Used on the same principle as the Mid Span Access Tool, (that enables accessibility multicolored buffer coated tight buffered fibers) dual blades will slit the tube lengthwise, exposing the buffer coated fibers. Fiber handling tools for instance a spatula or even a pick may help the installer to access the fiber needing testing or repair. After the damaged fiber is exposed a hand- stripping tool will be employed to eliminate the 250um coating in order to work with all the bare fiber. The next phase is going to be cleansing the fiber end and preparing so that it is cleaved. An excellent cleave is probably the most important factors of creating a low loss over a splice or perhaps a termination. A Fiber Optic Cleaver is really a multipurpose tool that measures distance through the end in the buffer coating to the point where it will probably be joined plus it precisely cuts the glass. Never forget to utilize a fiber trash-can for your scraps of glass cleaved off 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 are using a mechanical splice, you will want stripping tools, mechanical splices, isopropyl alcohol and 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 complete you have to inspect the final face in the connector with Secondary Coating Line. Being sure that light is becoming through either the splice or even the connection, a Visual Fault Locator can be utilized. This piece of equipment will shoot a visible laser down the fiber cable so you can tell there are no breaks or faulty splices. When the rhnnol light stops down the fiber somewhere, there is probably a break in the glass at that point. When there is more than a dull light showing on the connector point, the termination was not successful. The light should also pass through the fusion splice, if it will not, stop and re- splice or re-terminate.