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 several tool out there that would have made the work 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 make use of 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 FTTH Cable Production Line requires special tools and methods. Training is essential and there are many 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 task! Being proficient in fiber work will become increasingly necessary as the significance of data transmission speeds, fiber to the home and fiber to the premise deployments continue to increase.
Many factors set fiber installations aside from traditional electrical projects. Fiber optic glass is extremely fragile; it’s nominal outside diameter is 125um. The least scratch, mark or even speck of dirt will change the transmission of light, degrading the signal. Safety is important since you are working with glass that can sliver into your skin without having to be seen from the eye. Transmission grade lasers are very dangerous, and require that protective eyewear is important. This industry has primarily been coping with voice and data grade circuits which could tolerate some interruption or slow down of signal. The individual speaking would repeat themselves, or even the data would retransmit. Today we have been dealing with IPTV signals and customers who can not tolerate pixelization, or momentary locking in the picture. All the situations mentioned are cause for the customer to look for another carrier. Each situation could have been avoided if proper attention was given to the methods used when preparing, 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 underneath the jacket and Buffer Strippers will eliminate the acrylate (buffer) coating from the bare glass. A protective plastic coating is used to the bare fiber after the drawing process, but before spooling. The most frequent coating is a UV-cured acrylate, that is applied in 2 layers, resulting in a nominal outside diameter of 250um for that coated fiber. The coating is extremely engineered, providing protection against physical damage caused by environmental elements, like temperature and humidity extremes, exposure to chemicals, point of stress… etc. while also minimizing optical loss. Without it, the producer would be unable to spool the fiber without breaking it. The 250um-coated fiber will be the foundation for many common fiber optic cable constructions. It is often used as is also, particularly when additional mechanical or environmental protection is not required, such as within optical devices or splice closures. For additional physical protection and simplicity of handling, a secondary coating of polyvinyl chloride (PVC) or Hytrel (a thermoplastic elastomer that has desirable characteristics for use being a secondary buffer) is extruded over the 250um-coated fiber, enhancing the outside diameter approximately 900um. This sort of construction is called ‘tight buffered fiber’. Tight Buffered may be single or multi fiber and therefore are observed 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 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 bigger than the diameter in the fiber. Loose tube fiber features a space for that fibers to expand. In certain climate 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) yet others that are labeled ‘dry block’. You will find many loose tube fibers in Outside Plant Environments. The modular design of SZ Stranding Line typically holds up to 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 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-away from teams of fibers at intermediate points, without disturbing 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 like D-Gel is going to be needed. Each fiber is going to be cleaned with the gel cleaner and 99% alcohol. Clean room wipers (Kim Wipes) are a good option to use with all the cleaning agent. The fibers within a loose tube gel filled cable normally have a 250um coating so they tend to be more fragile compared to a tight-buffered fiber. Standard industry color-coding is additionally employed to identify the buffers as well since the fibers inside the buffers.
A ‘Rotary Tool’ or ‘Cable Slitter’ can be used to slit a ring around and through the outer jacketing of ‘loose tube fiber’. Once you expose the durable inner buffer tube, you can use a ‘Universal Fiber Access Tool’ which is designed for single central buffer tube entry. Used on the same principle since the Mid Span Access Tool, (that allows access to the 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 take away the 250um coating in order to work using the bare fiber. The next phase is going to be washing the fiber end and preparing it to be cleaved. A great cleave is among the most significant factors of making a low loss on a splice or perhaps a termination. A Fiber Optic Cleaver is really a multipurpose tool that measures distance through the end of the buffer coating towards the point where it will probably be joined and it precisely cuts the glass. Never forget to use a fiber trash-can for that scraps of glass cleaved from 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 work with a mechanical splice, you will need stripping tools, mechanical splices, isopropyl alcohol along with a mechanical splice assembly tool. When hand terminating a fiber you will require 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 end face from the connector with Sheathing Line. Being sure that light is becoming through either the splice or the connection, a Visual Fault Locator can be utilized. This device will shoot a visible laser down the fiber cable which means you can tell that we now have no breaks or faulty splices. If the rhnnol light stops down the fiber somewhere, there is probably a break in the glass in that point. When there is more than a dull light showing on the connector point, the termination had not been successful. The light should also pass through the fusion splice, when it does not, stop and re- splice or re-terminate.