Not long ago i watched my coworker disassembling a computer using only one tool. Was it the correct tool to do the job? Yes and no. It was the tool he had… it worked, however, there exists definitely several tool on the market that could have made the work easier! This case is definitely one which many fiber optic installers know all too well. As a gentle reminder, what percentage of you have used your Splicer’s Tool Kit (cable knife/scissors) to get rid of jacketing or even slit a buffer tube and then use the scissors to hack away at the Kevlar? Do you nick the glass? Have you accidentally cut through the glass and need to start over?
Correctly splicing and terminating optical fiber coloring machine requires special tools and methods. Training is essential and there are many excellent causes 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 still increase.
Many factors set fiber installations aside from traditional electrical projects. Fiber optic glass is quite fragile; it’s nominal outside diameter is 125um. The slightest scratch, mark as well as speck of dirt will change the transmission of light, degrading the signal. Safety factors important simply because you will work with glass that may sliver into your skin without having to be seen from the human eye. Transmission grade lasers are extremely dangerous, and require that protective eyewear is essential. 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 the data would retransmit. Today our company is coping with IPTV signals and customers who can not tolerate pixelization, or momentary locking from the picture. Each of the situations mentioned are cause for the client to search for another carrier. Each situation could have been avoided if proper attention was provided to the methods used in planning, installing, and maintaining fiber optic cables.
With that being said, why don’t we review basic fiber preparation? Jacket Strippers are used 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 under the jacket and Buffer Strippers will remove the acrylate (buffer) coating through the bare glass. A protective plastic coating is used to the optical fiber ribbon machine after the drawing process, but prior to spooling. The most typical coating is actually 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 due to environmental elements, including temperature and humidity extremes, exposure to chemicals, reason for stress… etc. while minimizing optical loss. Without this, the maker would struggle to spool the fiber without breaking it. The 250um-coated fiber will be the building block for most common fiber optic cable constructions. It is usually used as it is, especially when additional mechanical or environmental protection is not needed, such as within optical devices or splice closures. For extra physical protection and ease of handling, a secondary coating of polyvinyl chloride (PVC) or Hytrel (a thermoplastic elastomer which has desirable characteristics for use being a secondary buffer) is extruded on the 250um-coated fiber, increasing the outside diameter up to 900um. This type of construction is known as ‘tight buffered fiber’. Tight Buffered might be single or multi fiber and are seen 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 known as a buffer tube, that has an inner diameter which is slightly greater than the diameter in the fiber. Loose tube fiber features a space for the fibers to grow. In some climatic 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’ within this cavity (or space) yet others which can be labeled ‘dry block’. You can find many loose tube fibers in Outside Plant Environments. The modular design of loose-tube cables typically holds up to 12 fibers per buffer tube with a maximum per cable fiber count in excess of 200 fibers. Loose-tube cables could be all-dielectric or optionally armored. The armoring is utilized to protect the cable from rodents such as 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 also helps in the identification and administration of fibers within the system. When protective gel is present, a gel-cleaner including D-Gel is going to be needed. Each fiber will likely be cleaned with the gel cleaner and 99% alcohol. Clean room wipers (Kim Wipes) are a wonderful option to use with all the cleaning agent. The fibers inside a loose tube gel filled cable usually have a 250um coating so they tend to be more fragile when compared to a tight-buffered fiber. Standard industry color-coding can also be utilized to identify the buffers along with the fibers in the buffers.
A ‘Rotary Tool’ or ‘Cable Slitter’ may 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 use a ‘Universal Fiber Access Tool’ which is perfect for single central buffer tube entry. Used on the same principle since 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 such as a spatula or even a pick will help the installer to get into the fiber in need of testing or repair. When the damaged fiber is exposed a hand- stripping tool will be employed to remove the 250um coating so that you can assist the bare fiber. The next phase is going to be cleaning the fiber end and preparing it to be cleaved. An excellent cleave is among the most important factors of producing a low loss over a splice or even a termination. A Fiber Optic Cleaver is really a multipurpose tool that measures distance from the end of the buffer coating to the point where it will probably be joined plus it precisely cuts the glass. Never forget to employ a fiber trash-can for your 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 use a mechanical splice, you will require stripping tools, mechanical splices, isopropyl alcohol along with a mechanical splice assembly tool. When hand terminating optical fiber coloring machine 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.
Whenever a termination is complete you must inspect the final face in the connector using a Fiber Optic Inspection Microscope. Making sure that light is getting through either the splice or yphlby connection, a Visual Fault Locator can be used. This piece of equipment will shoot a visible laser down the fiber cable so that you can tell there are no breaks or faulty splices. If the laser light stops along the fiber somewhere, there is probably an escape inside the glass when this occurs. When there is greater than a dull light showing at the connector point, the termination was not successful. The light must also go through the fusion splice, if this does not, stop and re- splice or re-terminate.