How to distinguish the quality of fiber optic cable
Introduction of central bundled tube optical cable GYXTW-8A.
1. Outer sheath: Indoor optical cables are generally made of polyvinyl chloride or flame retardant polyvinyl chloride. The appearance should be smooth, bright, flexible and easy to peel. The outer skin of the cable with poor quality is not smooth, and it is easy to stick to the tight sleeve and aramid fiber inside.
The PE sheath of the outdoor optical cable should be made of high-quality black polyethylene. After the cable is formed, the outer sheath is flat, bright, uniform in thickness and free of small air bubbles. The outer skin of inferior optical cable is generally produced with recycled materials, which can save a lot of cost. Such optical cable skin is not smooth. Because there are many impurities in the raw material, the outer skin of the optical cable made has many tiny pits, which will crack and enter after a long time. water.
2. Optical fibers: Regular optical cable manufacturers generally use A-grade fiber cores from major manufacturers. Some low-cost and low-quality optical cables usually use C-grade and D-grade fibers and smuggled fibers of unknown origin. These fibers have complex sources and take a long time to leave the factory. It is often already wet and discolored, and multimode fibers are often mixed with single-mode fibers. Generally, small factories lack the necessary testing equipment and cannot make judgments on the quality of the fibers. Since such optical fibers cannot be distinguished by the naked eye, the common problems encountered in construction are: narrow bandwidth and short transmission distance; uneven thickness, which cannot be connected to the pigtail; the optical fiber lacks flexibility and breaks when the fiber is coiled.
3. Reinforced steel wire: The steel wire of the outdoor optical cable of the regular manufacturer is phosphating, and the surface is gray. This kind of steel wire does not increase the hydrogen loss after cabling, does not rust, and has high strength. Inferior optical cables are generally replaced by thin iron wires or aluminum wires. The identification method is easy to see that the appearance is white, and it can be bent at will when you hold it in your hand. The optical cable produced with such steel wire has a large hydrogen loss, and the two ends of the hanging optical fiber box will rust and break after a long time.
4. Steel armor: Regular production enterprises use longitudinally-wrapped steel strips with anti-rust paint on both sides, and ordinary iron sheets are used for inferior optical cables, usually only one side has been treated with anti-rust treatment.
5. Loose tube: The loose tube of the optical fiber in the optical cable should be made of PBT material. Such a tube has high strength, no deformation, and anti-aging. Inferior optical cables are generally made of PVC casing. The outer diameter of such a casing is very thin, and it is flattened when squeezed by hand, which is a bit like a straw for drinking beverages.
6. Fiber paste: The fiber paste in the outdoor optical cable can prevent the optical fiber from oxidizing. Due to the entry of moisture and moisture, the fiber paste used in the inferior optical fiber is very small, which seriously affects the life of the optical fiber.
7. Aramid, also known as Kevlar, is a high-strength chemical fiber, which is currently most used in the military industry. Military helmets and bulletproof vests are produced from this material. At present, only DuPont and Aksu in the Netherlands can produce it, and the price is about 300,000 tons. Both indoor optical cables and power overhead optical cables (ADSS) use aramid yarns as reinforcements. Due to the high cost of aramid fibers, low-quality indoor optical cables generally make the outer diameter very thin, so that a few strands of aramid can be used to save costs. Such an optical cable can easily be pulled and broken when passing through the tube. Because ADSS optical cable determines the amount of aramid fiber in the optical cable according to the span and wind speed per second, it is generally not afraid to cut corners. Kevlar is not included because we use the central bundled tube light armored optical cable for testing.
Eight, the diameter of the optical cable, for the central bundled tube optical cable, the diameter standard is generally about 7.5mm, plus or minus 0.2mm is also acceptable.