1. Outer Sheath: Indoor optical cables generally use polyvinyl chloride or flame-retardant polyvinyl chloride, and the surface should be smooth, bright, flexible and easy to detach. The smoothness of the outer sheath of the optical cable is not very good, and it is easy to adhere to the tight buffer and aramid yarn inside.

The PE sheath of the outdoor 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 bubbles. The outer sheath of inferior fiber optic cable is generally made of recycled raw materials, which can save a lot of cost. The outer sheath of such fiber optic cable is uneven. Because there are many residues in the raw material, the outer sheath of the made fiber optic cable has many tiny pits and pits. Water etc.

2. Optical fiber: Reliable optical fiber cable manufacturing companies generally use A-level cores from large factories. Some cheap and inferior optical cables generally use C-level and D-level optical fibers and smuggled optical fibers of unknown origin. This type of optical fiber takes a long time to leave the factory due to unknown sources. Usually it has been damp and faded, and single-mode fibers are often mixed in multimode fibers. Generally, small processing plants lack the necessary testing equipment to distinguish the quality of the fiber. Because human eyes cannot distinguish such optical fibers, the common problems encountered in the construction site are: narrow bandwidth and short transmission distance; uneven size and cannot be connected to the pigtail; the optical fiber lacks flexibility and the coil fiber is the case. The fiber could break easily during operating.(to be continued…)