Not long ago i watched my coworker disassembling a personal 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 multiple tool out there that would have made the task easier! This example is definitely one that many fiber optic installers know all too well. As a gentle reminder, what number of you have used your Splicer’s Tool Kit (cable knife/scissors) to remove jacketing or even slit a buffer tube and then utilize 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 SZ Stranding Line requires special tools and techniques. Training is very important and there are many excellent types of training available. Do not mix your electrical tools along with your fiber tools. Utilize the right tool for the task! Being familiar with fiber work will become increasingly necessary as the significance of data transmission speeds, fiber to the home and fiber for 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 affect the transmission of light, degrading the signal. Safety is important since you work with glass that can sliver to your skin without having to be seen through the human eye. Transmission grade lasers are very dangerous, and require that protective eyewear is important. This industry has primarily been dealing with voice and data grade circuits that could tolerate some interruption or slow down of signal. Anyone speaking would repeat themselves, or perhaps the data would retransmit. Today we have been coping with IPTV signals and customers who will not tolerate pixelization, or momentary locking from the picture. Each of the situations mentioned are cause for the customer to find another carrier. Each situation might have been avoided if proper attention was provided to the strategies used in planning, installing, and maintaining fiber optic cables.
Having said that, why don’t we review basic fiber preparation? Jacket Strippers are employed to eliminate 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 under the jacket and Buffer Strippers will remove the acrylate (buffer) coating from the bare glass. A protective plastic coating is used to the bare fiber after the drawing process, but prior to spooling. The most frequent coating is a UV-cured acrylate, that is applied by two layers, resulting in a nominal outside diameter of 250um for your coated fiber. The coating is very engineered, providing protection against physical damage brought on by environmental elements, like temperature and humidity extremes, exposure to chemicals, point of stress… etc. while minimizing optical loss. Without one, the producer would be unable to spool the fiber without having to break it. The 250um-coated fiber will be the building block for a lot of common fiber optic cable constructions. It is often used as it is, especially when additional mechanical or environmental protection is not needed, like inside of optical devices or splice closures. For further physical protection and simplicity of handling, a secondary coating of polyvinyl chloride (PVC) or Hytrel (a thermoplastic elastomer which has desirable characteristics to use as a secondary buffer) is extruded on the 250um-coated fiber, increasing the outside diameter up to 900um. This type of construction is called ‘tight buffered fiber’. Tight Buffered may be single or multi fiber and therefore are noticed 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 referred to as a buffer tube, which has an inner diameter which is slightly greater than the diameter in the fiber. Loose tube fiber has a space for the fibers to grow. In certain weather conditions, a fiber may expand and after that shrink over and over again or it may be subjected to water. Fiber Cables will sometimes have ‘gel’ in this cavity (or space) as well as others that are labeled ‘dry block’. You can find many loose tube fibers in Outside Plant Environments. The modular form of SZ Stranding Line typically holds approximately 12 fibers per buffer tube having a maximum per cable fiber count of more than 200 fibers. Loose-tube cables can be all-dielectric or optionally armored. The armoring can be used to safeguard 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-off of sets of fibers at intermediate points, without upsetting other protected buffer tubes being routed with other locations. The loose-tube design also helps in the identification and administration of fibers inside the system. When protective gel is present, 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 good choice to use using the cleaning agent. The fibers inside a loose tube gel filled cable usually have a 250um coating so that 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 used to slit a ring around and thru the outer jacketing of ‘loose tube fiber’. When you expose the durable inner buffer tube, you can utilize a ‘Universal Fiber Access Tool’ which is made for single central buffer tube entry. Used on the same principle because the Mid Span Access Tool, (which allows accessibility multicolored buffer coated tight buffered fibers) dual blades will slit the tube lengthwise, exposing the buffer coated fibers. Fiber handling tools like a spatula or a pick can help the installer to get into the fiber looking for testing or repair. Once the damaged fiber is exposed a hand- stripping tool will be employed to remove the 250um coating in order to work using the bare fiber. The next step will be cleansing the fiber end and preparing that it is cleaved. An excellent cleave is one of the most essential factors of creating a low loss on a splice or a termination. A Fiber Optic Cleaver is really a multipurpose tool that measures distance from your end of the buffer coating to the point where it will likely be joined and it also precisely cuts the glass. Remember to use a fiber trash-can for that scraps of glass cleaved off the fiber cable.
When performing fusion splicing you may need a Fusion Splicer, fusion splice protection sleeves, and isopropyl alcohol and stripping tools. If you use a mechanical splice, you will require stripping tools, mechanical splices, isopropyl alcohol along with a mechanical splice assembly tool. When hand terminating a fiber you will need 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 need to inspect the final face of the connector with Fiber Drawing Machine. Being sure that light is getting through either the splice or even the connection, a Visual Fault Locator can be utilized. This item of equipment will shoot a visible laser down the fiber cable so you can tell that we now have no breaks or faulty splices. When the rhnnol light stops down the fiber somewhere, there is probably a break in the glass at this point. When there is greater than a dull light showing in the connector point, the termination was not successful. The light should also go through the fusion splice, if this will not, stop and re- splice or re-terminate.