Multi-angle identification of optical cable quality

The quality of the optical cable will affect the quality of network communication, as well as the speed and service life of the network. There are many factors that affect the quality of optical cables.So, how to distinguish the quality of optical cable?

The quality of the optical cable can be identified from the following aspects:

• Sheath: Indoor optical cables are generally made of polyvinyl chloride or flame-retardant polyvinyl chloride, and the appearance should be smooth, bright, flexible, and easy to peel off. The outer sheath of the optical cable with poor quality has poor finish, and it is easy to adhere 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 sheath is flat, bright, uniform in thickness, and free of small bubbles. The outer sheath of inferior optical cables is generally produced with recycled materials, which can save a lot of cost. The outer sheath of such optical cables is not smooth. Because there are many impurities in the raw materials, the outer sheath of the optical cable made has many very small pits, which will crack and enter water after a long time.

Optical fiber: Regular optical cable manufacturers generally use A-level fiber cores from major manufacturers. Some low-priced and inferior optical cables usually use C-level, D-level optical fibers and smuggled optical fibers from unknown sources. Moisture and discoloration, and multimode fiber is often mixed with single-mode fiber, and generally small factories lack the necessary testing equipment, so they cannot judge the quality of the fiber. Because the naked eye cannot distinguish such optical fibers, the common problems encountered in construction are: narrow bandwidth and short transmission distance; uneven thickness, which cannot be connected with pigtails; optical fibers lack flexibility, and they will break when they are bent.

• Reinforced steel wire: The steel wire of the outdoor optical cable of regular manufacturers is phosphating-treated, and the surface is gray. This kind of steel wire does not increase hydrogen loss after being cabled, does not rust, and has high strength. Inferior optical cables are generally replaced by thin iron wires or aluminum wires. The identification method is very easy-the appearance is white and can be bent at will when pinched in the hand. The optical cable produced by such steel wire has a large hydrogen loss, and after a long time, the two ends of the optical fiber box will rust and break.

• Steel armor: Regular manufacturers use double-sided anti-rust coating longitudinally wrapped steel strips, and low-quality optical cables use ordinary iron sheets, usually only one side of which has been treated with anti-rust.

• Loose tube: The loose tube containing 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 generally use PVC as the sleeve. The outer diameter of such a sleeve is very thin, and it will be flat when pinched by hand, a bit like a drinking straw for us to drink.

• Ointment: The ointment mainly includes jelly and filling compound. Under normal circumstances, jelly should fill the entire loose tube, and filling compound should fill every gap in the cable core under pressure. The jelly is half-filled or less, and some filling compound is only applied to the outside of the cable core, and some are filled at both ends of the cable and not filled in the middle. In this way, the optical fiber will not be well protected, affecting the transmission performance such as optical fiber attenuation, and the poor waterproof performance will not meet the national standard. Once the optical cable accidentally seeps into water, the entire link will be water seeped and scrapped. Under normal circumstances, even if there is an accidental water seepage, it is only necessary to repair a section of the water seepage, and there is no need to start over. If poor ointment is used, the above problems will also occur, and the poor thixotropy of the ointment may cause microbending loss in the optical fiber, and the transmission characteristics of the entire link are unqualified; if the ointment is acidic, it will also interact with the optical fiber in the cable The metal material undergoes H evolution reaction to precipitate hydrogen molecules, while the attenuation of the optical fiber will increase rapidly when encountering H, causing the entire link to interrupt the transmission.

Aramid yarn: Also known as Kevlar, it is a high-strength chemical fiber that is most used in the military industry. Military helmets and bulletproof vests are produced from this material. There are few places in the world that can produce aramid fiber, and the price is expensive. Indoor optical cables and electric overhead optical cables (ADSS) both use aramid yarns as reinforcements. Due to the high cost of aramid, inferior indoor optical cables generally have a very thin outer diameter, so that a few strands of aramid can be used to save costs. Such an optical cable is easily broken when passing through the pipe. Because the ADSS optical cable determines the amount of aramid used in the optical cable according to the span and the wind speed per second, it is generally not dare to cut corners.

• Water-blocking tape: The water-blocking tape or water-blocking yarn used for optical cables passes through the strong water-absorbing properties of the superabsorbent resin that is evenly distributed inside the product. Non-toxic resin can quickly absorb water several times its own weight. Moreover, once the water-blocking powder meets water, it will immediately expand the gel. At this time, no matter how much pressure is applied to it, the water will not be squeezed out. Therefore, the cable core is covered with a water-absorbent resin-containing water-blocking tape. In case the outer wall of the optical cable is damaged, the super-absorbent resin in the wound part will play a sealing effect due to expansion, and the ingress of water can be prevented to a minimum. Inferior optical cables usually use non-woven fabrics or paper tapes. Once the outer sheath of the optical cable is damaged, the consequences will be very serious.