answer：The fiber is a kind of subtle and flexible medium for transmitting light beam. It is the abbreviation of optical fiber, the most commonly used optical fiber used for comprehensive wiring is the glass core of light transmission. The core is usually a double-layer concentric cylinder of very small cross-sectional area made of quartz glass, which is brittle and therefore requires an applied protective layer. Fiber is far beyond its own meaning in terms of its usage. It can be either an optical fiber core or a fiber optic cable, or an optical fiber wiring system or even an optical fiber communication system. However, in order to accurately define each partial product of an optical fiber wiring system, a general optical fiber refers to a core portion, and the optical cable is a finished cable composed of an optical fiber as a transmission unit.

answer：According to the fiber core category, it can be divided into single-mode optical cable and multi-mode optical cable according to the laying mode: self-bearing overhead optical cable, pipeline optical cable, armored ground optical cable and submarine optical cable. According to the cable structure: bundle-type optical cable, layer-hinged optical cable, framework type optical cable, clinched optical cable, belt type optical cable, non-metal optical cable and branching optical cable. Optical cable for long-distance communication, outdoor optical cable, mixed optical cable and built-in optical cable Note: This company adopts indoor set-up type, outdoor central bundle pipe type, layer-hinged optical cable, belonging to pipeline optical cable, short-transit outdoor optical cable and built-in optical cable.

answer：Multi-mode optical fiber: The optical fiber with multiple modes of electromagnetic wave can be spread, and the single-mode fiber can only conduct single-mode fiber. Compared with single-mode fiber, the fiber core is large, but the dispersion is much larger, the transmission capacity is small, and the transmission distance is also short.

answer：In the national standard of GB50311, the transmission distance of multi-mode optical cable is 2km, and the transmission distance of single-mode optical cable is 3km. Note here is 2km, 3km is the limit specified in GB50311 standard range, not the medium limit. Generally, the use of multi-mode optical cables in communication is within 500 meters, while the non-relay communication distance of a single-mode optical cable is typically 60 km.

answer：62.5/ 125 means that the outer diameter of the core is 62.5 µm, and the external diameter plus the coating layer is 125 µm. 50/ 125 refers to a core having an outer diameter of 50 µm, and the external diameter plus the coating layer is 125 µm. 9/ 125 refers to a core having an outer diameter of 9 µm, plus an outer diameter of 125 µm after the coating layer.

answer：1. The non-armored has only one layer of metal, or a aluminum strip or a steel strip. 2. Light armor refers to that having two layers of metal, such as: one layer of aluminum strip inside, with a steel strip added outside. 3. The heavy-armor refers to that having two metal layers and a PE sheath is added between the two layers of metal layers.

answer：Both of these are outdoor optical cables. 1. The country defines that each loose sheath can contain up to 12 core fiber cores, and the central bundle tube type structure determines that there is only one loose sleeve in the center bundle tube, so that the central bundle tube can only have 12 cores (24 cores currently made by some manufacturers, but 24 cores are not standard, We do not recommend it) . It's relatively cheap, so we recommend the central bundle tube within 12 cores. 2. The layer hinge structure is the middle reinforcing steel wire, which is surrounded by one or more loose sleeves around the reinforcing steel wire, so that the layer hinge can support the specification of more than 12 cores. At present, our company can support the production of 144 cores of optical cables.

answer：1. The attenuation of the optical cable will also increase when the hydrogen loss is caused by tension, pressure, bending or contact of water. 2. In the construction, the optical cable can be pulled, even if the optical cable is pulled out seriously under the condition of serious damage of the optical cable disc, the quality accident such as cable twisting, stretching deformation, skin scratch and other quality accidents often occur, and the fiber breaking can occur seriously, which greatly affects the use of the optical cable. 3. When the bending radius is too small for construction, it is not right. It is easy to cause the refraction loss to be too large and the dispersion is increased, the time is long, and the fiber breaking phenomenon may occur. At the same time, the bending radius is too small to cause the cable sleeve or the center reinforcing member (steel wire) to be broken, and the optical cable is twisted; The sheath and even steel/ glass fiber cracking, optical cable, deformation, etc., both cause the optical cable to be damaged, generate physical change, the OTDR test often has a step in the non-joint position, and the outer sheath of the optical cable has no obvious trace, and after dissection of the optical cable, it is found that the sleeve is obviously crushed.

answer：1. Re-clean the connector end faces of all the tested links and reference jumpers. Reconnect to ensure that all connectors are fully cut in in the fiber optic adapter. 2. Check whether the bending radius of optical cable and jumper meets the standard requirements, especially the cable in the fiber box and whether the bending radius is too small.3. Re-test, if the welding method is not able to be adopted, the welding method is followed by the welding of the tail fiber, the connection head is replaced in the terminating manner, and the new test shall be carried out.4. If it is not passed, it may be that the fiber optic cable itself is damaged. What's the difference between fiber optic adapters and fiber optic frames ST, SC, LC, FC fiber optic connectors?