Fiber Transmission Communication Network – Optical Terminal Box

Optical Fiber Termination Box in short OTB, optical terminal box is mainly used for the cable ends fixed, cable and pigtail splice and the remainder fiber asylum and protection. The communication network of fiber optic transmission optical cable terminal box series terminal wiring of auxiliary equipment, suitable for indoor fiber optic cable directly and branching connection of the fiber optic connector play a protective role.

The Material Performance

Optical cable terminal box where the parts are made of materials should have anti-corrosion properties, such as corrosion resistance should be treated with preservatives; Its physical and chemical properties must be stable; must be compatible between the various materials.

And sheath compatible with the cable jacket and wiring pigtail. In order to prevent corrosion and other electrical damage, these materials must also be compatible with other commonly used materials in the device.

Appearance of cable terminal box should be completer shape, no glitches, no bubbles, no cracks and voids, meta-warping element impurities and other defects. All background color shold be uniform and continuous. Beautiful appearance, convenient construction connecting additional attenuation reasonable structure, the fiber to strengthen the core fixed in the terminal box, cable metal outer sheath connected ground wire leads function applies to both the ribbon cable and fiber optic cable. Unique design, the terminal box on the 19-inch, wall-mounted terminal box.

Cable terminal box of the optical properties of the remaining fiber is coiled in the set fibers and optical fiber and fiber optic connectors, fiber optic terminal box installation of the operating additional attenuation.

Mechanical properties after the following tests, the cable terminal box box body and box should change, if necessary, for the fiber-ray examination.

1.Stretch: cable terminal box with a fiber optic cable should be able to withstand the axial tensile strength of not less than 500N, with either a wiring pigtail can withstand axial tensile strength of not less than 5N.
2. Flattening: The cable terminal box on each side of the box body should be able to withstand the vertical static pressure of not less than 200N.
3. Torsion: cable terminal box should be able to withstand the torsion angle.

Electrical performance

1. Insulation resistance: Cable connector box of metal components and optical metal reinforcing core fiber optic cable between the metal components, the insulation resistance between the cable metal parts and ground should not be less than 2 * 104MΩ [test voltage of 500V (DC).

2. Dielectric strength: cable terminal box with cable metal strengthening core fiber optic cable between the metal components, cable metal structures between the role of 15KV DC 1min, no breakdown, no flashover.

Optical Performance

The remaining fiber cable terminal box is coiled within the splice tray fiber and fiber optic connectors, cable terminal box installation of the operating there should be no additional attenuation.


The splice closure is two pieces of fiber optic cable connection. The terminal box is the tip of the cable access, and then through the patch cord access optical switch. Therefore, the terminal box is usually installed in the 19-inch rack can accommodate fiber optic cable ends quantity more. The splice closure is two pieces of fiber optic cable connection. Terminal box is connected to the fiber optic cable with pigtail play a protective role. Indoor terminal box can be used for practical work with but very little splice closure when the terminal box uses not the same. 1. the transfer box can be divided into the cable transfer box and cable boxes. Their role in the user front-end wiring use. 2. Breakout boxes generally refers to the splice box, also known as fiber optic splice closure in some places, especially radio and television system, also known as optical splice pack, its role is to protect the cable connector does not damage by the outside world. Patch panel fiber optic patch panels and cable distribution frame, the role like the transfer case, but it is used in the engine room of the operators.


Optical cable terminal box as a carrier of information transmission, fiber optic hardware as an information transmission medium, has become an important pillar of modern communication. optical cable terminal box technology from theory to the field of engineering technology experienced a few decades, to the realization of today’s high-speed fiber-optic communications, before and after the birth of the fiber-optic communications technology and in-depth development of information and communication in the history of an important reform.

Optical cable terminal box is widely used in telephone, if farmers network systems, data, image transmission system, CATV cable TV series for indoor fiber optic cable through power connection and branch connection, play a pigtail disc storage and protection of joint role, made of cold-rolled steel plate electrostatic spray, design, reasonable structure, appearance before a large fiber to strengthen the core fixed in the terminal.

How To Distinguish Between Good or Bad The Quality of Fiber Optic Cable

1. Ointment. Ointment is mainly fine paste paste with cable, fiber paste normally should be full of the casing, cable paste should be under pressure every crevice of cable core. Now, fiber paste sufficient half-full or less the practice of cable extract some just wipe a layer of the cable core, while others are in the middle of the fiber optical cable two charge is not sufficient. This will make the fiber are not good protection, the impact of the transmission performance of optical fiber attenuation, poor water resistance less than the national standard, once the cable accidental seepage will cause the whole links seepage scrapped. Under normal circumstances, even accidental seepage simply repair a section of water seepage can, you do not need to start over. (National standard water-blocking performance: three meters of fiber optic cable, one meter of water column pressure round the clock impermeable.) If use poor ointment will also appear to be happening, and may because the ointment thixotropic, cause the fiber to cause microbending loss, the link transmission characteristics failed; ointment with acidic also with fiber optic cable metal materials analysis H reaction precipitation of hydrogen molecules, fiber case of H decay will increase dramatically, resulting in the entire link interrupt transmission.

2. Sheath. The cable sheath is necessary to adapt to many different complex climate, but also to ensure the stability of the long-term (at least 25 years). Cable jacket not only have a certain strength, low thermal deformation, wear, water permeability, heat-recoverable, and coefficient of friction, but also should be strong resistance to environmental performance materials processing features. Less or bad sheath material cracking, water seepage through factory acceptance, but the quality is defective use for some time, using recycled plastics to replace quality polyethylene sheath material is more serious. High quality sheath material made of fibe optic cable, a cable skin smooth, bright, uniform thickness, no bubbles, otherwise the coarse skin of fiber optic cable, and a lot of very small pit, and because of the thin thickness, the entire outer diameter of the fiber optic cable will be muach smaller than the high quality cable. Indoor fiber optic cable, usually made of high quality flame retardant PVC, the appearance should be smooth, bright, good flexibility, easy to peel; and otherwise poor skin finish, easy and tight buffer fiber, aramid adhesion phenomenon.

3. Steel, aluminum. Steel, aluminum cable is mainly used to protect the fiber from mechanical side pressure, moisture and other effects, better cable typically use chrome-plated steel strip. Low quality fiber optic cable to only one side done ordinary iron rust treatment, or black (uncoated steel), instead of chrome-plated steel strip, over time, the cable will appear corroded, fiber optic hydrogen loss also aggravate andits easy separation do not constitute the sheath bonded sheath tide also very poor performance; of some places tinned strip instead of chrome-plated steel strip, tin-plated surface of the strip, the bubble is inevitable, so in humid, prone to corrosion under the conditions of the atmosphere and surface condensation or water, especially under acidic conditions, corrosion faster. The tin plating layer is poor in heat resistance, melting at 232 degrees Celsius, only the application of due to squeeze sheaths when the high temperature, such that the peel strength uncertainty affect the cable anti-surge performance. Chromium melting point of 1900 degrees Celsius, chemically very stable at room temperature in air or water will not rust, corrosion resistance, very good resistance to environmental performance, easily oxidized due to surface passivation layer is formed so good. Aluminum generally failed thermal paste method coated aluminum instead of cast qualified coated aluminum, which also affect cable performance.

4. Steel wire. The steel wire in the fiber optic cable mainly used to protect optical fiber from the mechanical tension. Good cable typically use for phosphating steel wire, high modulus short-term tension 1500N and 3000N. And low-quality fiber optic cable will be a very small diameter wire or ordinary steel instead of the one hand, easy to rust; On the other hand, is far less than the tensile strength 1500N construction may strain the fiber. High modulus phosphide stell wire is generally gray color, good toughness, not easy to bend; the alternative wire generally pinch in your hand can be bent a long time, the two rust fracture hanging cable box.

5. Loose tube. The installed fiber loose tube fiber optic cable is generally used polymer PBT material (poly (butylene terephthalate)), this loose tube, high strength, no deformation, anti-aging. Poor quality loose tube fiber optic cable is sometimes replaced with other materials, diameter thin, hand pinch flat, no different from drinking straw, can not afford the protective effect of the fiber.

6. Waterproof tape. Fiber optic cable with waterproof tape or water blocking yarn through the inside of the product showed a uniform distribution of high water-absorbing resin has strong water absorption, under the combined effect of the osmotic pressure, affinity, rubber elastic, super absorbent resin inhalation several times the weight of water. Further, the water-blocking powder once with water swollen gel will instantly, regardless to its much pressure is applied, moisture nor is extruded. Thus, with a water-absorbent resin containing water-blocking tape coated cable core, in case the outer wall of the fiber optic cable is damaged, the wound portion of the high water-absorbent resin to play due to expansion of the sealing effect, can prevent the entry of water to a minimum. Low-quality fiber optic cable commonly used non-woven fabric or paper tape, once the cable jacket is damaged, the consequences will be very serious.

7. Kevlar. Kevlar is a high-strength chemical fiber, most in the field of military-industrial complex, a bullet-proof vest is the producer of this material. It is a patented product of DuPont, is the major cost components of the indoor fiber optic cable, tight buffer fiber indoor cable is mainly used to protect against mechanical tension. Due to Kevlar high cost, poor quality of indoor fiber optic cable outer diameter is generally made ​​very thin, so you can by reducing the few shares aramid cost savings, or use an appearance similar to Kevlar polyester yarn instead (more common) polyester yarn almost can not bear what tension. So that the optical fiber laying easily strain or pull off.

8. Optical fiber. The fiber optic cable core raw materials, the good cable commonly used manufacturers of high quality core. Low-quality fiber optic cable is usually lower fiber and unsolicited fiber, these fibers due to the complex sources, quality is difficult to guarantee, sometimes multimode fiber often mixed with single-mode fiber, and the general lack of small factories necessary testing equipment, not fiberquality of judgment, more so the quality is difficult to be guaranteed. In addition, some bought with cheap short segment later cabled fiber splicing. The naked eye can not distinguish this fiber, the problems often encountered in the construction are: low transmission rate, short distance, fiber attenuation, not and pigtail docking, lack of flexibility, easily broken plate filament when even a single fiber a multi-mode, the other end is single-mode.

9. Coloring ink. Distinguish fiber in order to facilitate the construction of national standards be with bright color and high-quality fiber optic cable are standard in high-quality ink colored fiber loose tube, the color is very clear and easy to fall off, while the low-quality fiber optic cable is used poor qualityink coloring or simply coloring and inferior ink colors are vivid and sometimes easy to dissolve in the fiber paste the color can not be distinguished, not colored even more great inconvenience to the construction.

10. Product packaging. The fiber optic cable commonly used packaging wooden plate or the iron wooden tray into the shaft, the outside of the plate sealed wooden seal plate to ensure that the bulky fiber optic cable throughout the transit force, bending radius conditions within the scope of the standard requirements. Low-quality fiber optic cable in order to save costs, generally very poor packaging tray, transported to the destination is almost close to falling apart, and some simply do not have the disk, look around cable is shipped, or the disc do not have to seal the wood.

In summary, optical fiber cables real good or bad from the structural design, integrated the difference between the pros and cons of the timber material and production process. Because the cable is not yet a large number of popular, low-quality products, while a lot of hidden dangers, many users even integrators do not understand the line is still used regardless of settings.

It is for this reason that the negative impact of low-quality fiber optic cable industry will be even greater, because the fiber optic cable itself, its value is not significant, but the cost of laying process (direct burial, aerial, wearing a tube) were truly amazing.and time-consuming, coupled with its entire communication link based medium, so if there are problems, no matter how expensive your hardware devices at both ends of the high-end, the entire system will be, without exception, completely paralyzed, will be a very long period of repair, resulting in the loss of thousands of times the difference between the pros and cons.