Not long ago 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 job easier! This example is unquestionably one that many fiber optic installers know all too well. As a gentle reminder, how many 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 have to start over?
Correctly splicing and terminating SZ Stranding Line requires special tools and techniques. Training is very important and there are many excellent sources of training available. Do not mix your electrical tools with your fiber tools. Utilize the right tool for the job! Being experienced in fiber work can become increasingly necessary as the significance of data transmission speeds, fiber to the home and fiber for the premise deployments continue to increase.
Many factors set fiber installations aside from traditional electrical projects. Fiber optic glass is very fragile; it’s nominal outside diameter is 125um. The least scratch, mark or even speck of dirt will impact the transmission of light, degrading the signal. Safety factors are important simply because you are working with glass that can sliver to your skin without being seen by the human eye. Transmission grade lasers are very dangerous, and require that protective eyewear is a must. This industry has primarily been dealing with voice and data grade circuits that could tolerate some interruption or slow down of signal. The individual speaking would repeat themselves, or perhaps the data would retransmit. Today we are dealing with IPTV signals and customers that will not tolerate pixelization, or momentary locking from the picture. All the situations mentioned are cause of the customer to search 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 utilized 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 eliminate the acrylate (buffer) coating from the 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 that coated fiber. The coating is very engineered, providing protection against physical damage due to environmental elements, like temperature and humidity extremes, being exposed to chemicals, point of stress… etc. while also minimizing optical loss. Without one, the manufacturer would be unable to spool the fiber without breaking it. The 250um-coated fiber is the foundation for many common fiber optic cable constructions. It is often used as is also, especially when additional mechanical or environmental protection is not needed, like within 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 that has desirable characteristics to use as being a secondary buffer) is extruded over the 250um-coated fiber, increasing the outside diameter as much as 900um. This type of construction is known as ‘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 for 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 that is slightly greater than the diameter from the fiber. Loose tube fiber has a space for the fibers to grow. In certain climate conditions, a fiber may expand and then shrink again and again or it may be in contact with water. Fiber Cables will sometimes have ‘gel’ within this cavity (or space) yet others which are labeled ‘dry block’. You will find many loose tube fibers in Outside Plant Environments. The modular design of FTTH Cable Production Line typically holds up to 12 fibers per buffer tube having a maximum per cable fiber count of over 200 fibers. Loose-tube cables can be all-dielectric or optionally armored. The armoring is used to safeguard 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-off of groups of fibers at intermediate points, without interfering with 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 exists, a gel-cleaner including D-Gel will be needed. Each fiber is going to be cleaned with all the gel cleaner and 99% alcohol. Clean room wipers (Kim Wipes) are a great decision to use with the cleaning agent. The fibers within a loose tube gel filled cable normally have a 250um coating therefore they are more fragile than a tight-buffered fiber. Standard industry color-coding can also be employed to identify the buffers as well as the fibers inside the buffers.
A ‘Rotary Tool’ or ‘Cable Slitter’ can be employed to slit a ring around and through 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 perfect 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 like a spatula or a pick can help the installer to access 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 washing the fiber end and preparing it to be cleaved. A good cleave is probably the most significant factors of making a low loss over a splice or even a termination. A Fiber Optic Cleaver is a multipurpose tool that measures distance from your end in the buffer coating to the point where it will likely be joined and it precisely cuts the glass. Always remember to employ a fiber trash-can for the scraps of glass cleaved off of the fiber cable.
When performing fusion splicing you might 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 as well as 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.
Each time a termination is finished you need to inspect the conclusion face in the connector with Optical Fiber Coloring Machine. Making sure that light is to get 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 which means you can tell there are no breaks or faulty splices. When the rhnnol light stops down the fiber somewhere, there is most probably a break in the glass at this point. When there is over a dull light showing in the connector point, the termination was not successful. The light must also move through the fusion splice, when it will not, stop and re- splice or re-terminate.