How to distinguish the quality of optical fiber and cable
1、 Outer layer: PVC or flame-retardant PVC is generally used for indoor optical cable, and the appearance shall be smooth, bright, flexible and easy to peel. The outer surface of poor quality fiber optic cable is not smooth and easy to adhere to the inner dense skin and aramid fiber.
The polyethylene sheath of outdoor optical cable shall be high-quality black polyethylene, with smooth and bright cable sheath, uniform thickness and no small bubbles. The outer skin of inferior optical cable is generally made of recycled materials, which can save a lot of costs. The outer skin of this kind of optical cable is not smooth, because there are many impurities in the raw materials, and the outer skin of the optical cable made has many small pits, which will crack and overflow for a long time.
2、 Optical fiber: ordinary optical cable manufacturers generally use metal fiber cores, and some low-cost low-quality optical cables generally use grade C and D optical fibers and unidentified optical fibers. The optical fiber source is complex, the delivery time is long, and it often feels wet and discolored, while multi-mode optical fibers are often mixed with single-mode optical fibers, while general small factories lack of detection equipment, so it is impossible to judge the quality of optical fibers. Because the optical fiber cannot be distinguished by the naked eye, the common problems in construction are: narrow bandwidth, short transmission distance; uneven thickness, unable to connect with the tail fiber; lack of elasticity of the optical fiber, when the disk optical fiber is bent, it will break.
3、 Strengthen the wire: the normal production wire of the outdoor optical cable manufacturer is phosphatized, and the surface is gray. Such wire entering the cable will not increase hydrogen damage, rust and high strength. The inferior optical cable is generally replaced by thin wire or aluminum wire. This recognition method is easy to appear white, and can be bent at will when pinched in the hand. With the occurrence of hydrogen damage to the wires and cables, the fiber boxes suspended at both ends will rust and break over a long period of time.
4、 Steel armour: conventional production enterprises use double-sided anti rust paint to longitudinally bind grain steel strip, and inferior optical cables use ordinary iron sheet, usually only one side is used for anti rust treatment.
Five, loose sleeve: the optical cable installed in loose sleeve should be made of PBT material, so that the casing has high strength, no deformation and anti-aging. The inferior optical cable is usually made of PVC casing, so the outer diameter of the casing is very thin, and it is flattened with a pinch of hand, which is a bit like the straw we drink.
6、 Fiber paste: fiber paste in outdoor optical cable can prevent fiber oxidation. Due to moisture entering into the moisture, fiber paste is very few, which seriously affects the service life of fiber.
7、 Aramid fiber, also known as Kevlar, is a kind of high strength chemical fiber, which is widely used in military industry at present. Helmet and bullet proof vest are made of this material. At present, only DuPont and Aksu of the Netherlands can produce it in the world, with a price of about 300000 tons. Indoor optical cable and power overhead optical cable (ads) are made of aramid fiber yarn. Because the cost of aramid fiber is high and the outer diameter of inferior indoor optical cable is usually very thin, several aramid fibers can be used less to save cost. This kind of cable is easy to break when it has thread. Because ads cable is based on span and wind speed per second to determine the use of aramid cable, generally dare not cut corners. Because we used a light armored cable with a central bundle, it didn't include Kevlar.
8、 The diameter of the cable, for the central bundle cable, the diameter standard is generally about 7.5mm, plus or minus 0.2mm. Let's use a caliper to measure the diameter of a cable.