Fiber optic cable is a new generation of transmission media, compared with copper media, both in terms of security, reliability, and network performance have been greatly improved. In addition, the bandwidth of fiber optic transmission greatly exceeds that of copper cable, and it supports of larger connection distance of more than two kilometers. It is an inevitable choice for the formation of large-scale networks. With good anti-electromagnetic interference, confidentiality, speed, transmission capacity, and other advantages.
1. Outer sheath
1.1 Indoor fiber optic cable outer sheath is generally made of polyvinyl chloride (PVC) or flame-retardant polyethylene or polyurethane (LSZH). The outer skin is smooth, shiny, flexible, easy to peel, and other characteristics. Poor quality fiber optic cable outer skin smoothness, easy and tight sleeve, aramid sticky edge.
1.2 Outdoor fiber optic cable outer sheath should be made of high-quality black polyethylene (HDPE, MDPE), the outer skin should be smooth, bright, uniform in thickness, and no bubbles after cable formation. Inferior quality fiber optic cable sheaths are mostly produced using recycled materials, and poor quality fiber optic cable skin is rough. This is due to the raw materials within a lot of impurities (lime powder), as shown in the outer skin of the cable has a lot of very small pits. If bent several times the outer sheath of the cable will be white, and the cable will be laid for a period of time after the outer skin cracks, and water seepage.
2. Optical fiber
Genuine fiber optic cable manufacturers will use the large manufacturers of A-grade fiber core. Low-priced low-quality fiber optic cable usually uses C-grade, D-grade fiber, and smuggled fiber of unknown origin, these fibers are complex due to the source, the factory time is long, often damp discoloration, and multimode fiber is often mixed with single-mode fiber. The general small factory lacks the necessary testing equipment and cannot judge the quality of optical fiber. Because the naked eye can not identify these fibers. The problems often encountered in construction are: narrow bandwidth, short transmission distance; thick and thin uneven, can not, and pigtail docking. Lack of flexibility of the fiber, coiled fiber is very easy to fracture.
3. Strengthen the steel wire
Regular manufacturers of outdoor fiber optic cable steel wire are phosphate treatment, the surface is gray, such steel wire into the cable does not increase hydrogen loss, no rust, high strength. Most of the poor-quality fiber optic cable is replaced with fine wire or aluminum wire. Identification method, that is, the appearance of white, pinched in the hand can be bent at will. With such wire production of fiber optic cable in the future will produce additional hydrogen loss, and at the same time, for a long time, the two ends of the link fiber box will rust and fracture.
4. Armored steel tape
Genuine manufacturers use double-sided brush anti-rust plastic-coated longitudinal wrapping pattern steel tape. Inferior quality fiber optic cable is used in ordinary iron, usually, only one side has done anti-rust treatment.
5. Fiber optic casing
Fiber optic cable wrapped in a loose casing should be used as PBT material, this material casing has high strength, non-deformation, and anti-aging. Inferior optical cable casing is usually produced with PVC material, so the outer diameter of the casing is very thin and soft, with a hand squeeze flat, no different from the drinking straw, can not be a good protection of optical fiber.
6. Fiber paste
Outdoor fiber optic cable fiber paste can prevent the fiber due to moisture and the silver pattern, hydrogen loss, and even fracture. Poor quality fiber optic cable with little fiber paste, the naked eye can observe a little bubble. Or the use of poor quality fiber paste seriously shortens the service life of fiber optic cable.
7. Aramid
Also known as Kevlar, is a high-strength chemical fiber, currently, the most in the military industry, military helmets, and bulletproof undershirts is the use in this material production. At present, the market above the aramid is mainly for the United States DuPont brand. Indoor fiber optic cable and power overhead fiber optic cable (ADSS) are used aramid yarn for reinforcing parts. Because of the high cost of aramid (200000 million yuan/ton), poor quality indoor fiber optic cable generally makes the outer diameter very thin, so you can save costs by reducing a few strands of aramid, this kind of fiber optic cable is easy to be pulled off when wearing the tube.
8. Cable paste
Outdoor fiber optic cable inside the fiber paste is tied to the outside of the fiber casing to protect the cable from moisture. High-quality cable paste mixed evenly, long-term use will not have separation. The poor quality of fiber optic cable inside, the cable paste will volatilize, or fill the fill is not enough to affect the fiber optic cable moisture barrier performance.