1、 Outer skin: PVC or flame retardant PVC is generally used for indoor optical cable, and the surface shall be smooth, bright, flexible and easy to peel. The outer surface of the optical cable with poor quality is not smooth and easy to adhere to the inner sleeve and aramid fiber.

PE sheath of outdoor optical cable shall be made of high-quality black polyethylene, with smooth, bright, uniform thickness and no small bubbles after cabling. The outer skin of low-quality optical cable is generally produced with recycled materials, which can save a lot of costs. The outer skin of such optical cable 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 water will enter after a long time.

2、 Optical fiber: Regular optical fiber cable manufacturers generally use A-grade fiber cores from large manufacturers. Some low-cost and low-quality optical cables usually use C-grade and D-grade optical fibers and smuggled optical fibers of unknown origin. These optical fibers have become damp and discolored due to their complex sources and long delivery time. In addition, multimode optical fibers are often mixed with single-mode optical fibers. Small manufacturers generally lack the necessary testing equipment and cannot judge the quality of optical fibers. Because the naked eye can not distinguish such optical fiber, the common problems encountered in construction are: very narrow bandwidth, short transmission distance; The thickness is uneven, and it cannot be connected with the pigtail; The optical fiber lacks flexibility and breaks at a bend when winding.

3、 Reinforcing steel wire: the steel wire of outdoor optical cable of regular manufacturer is phosphatized, and the surface is gray. Such steel wire does not increase hydrogen loss, rust, and has high strength after cabling. The low-quality optical cable is generally replaced by thin iron wire or aluminum wire, and the identification method is easy -- the appearance is white, and it can be bent at will when held in the hand. The hydrogen loss of the optical cable produced with such steel wire is large, and the two ends of the hanging optical fiber box will rust and fracture after a long time.

4、 Steel armouring: the regular production enterprises use the longitudinal wrapped steel strip with anti rust coating on both sides. The low-quality optical cable uses ordinary iron sheet, and usually only one side has been treated with anti rust.

5、 Loose tube: PBT material shall be used for loose tube of optical fiber installed in optical cable, which has high strength, no deformation and aging resistance. Poor quality optical cables generally use PVC as the casing. The outer diameter of such casing is very thin, and it will be flat when you pinch it with your hand. It is a bit like a straw for drinking drinks.