With the ever-increasing bandwidth of contemporary 光纖線 data transmission, the demand for fiber optic cables is also rising, and many unqualified fiber optic cable products have appeared on the market. Here is how to distinguish the quality of fiber optic cables:
1. Ointment. The ointment mainly includes fiber paste and cable paste. In the case of abnormalities, the fiber paste should cover all the loose tubes, and the cable paste should cover every crack of the optical cable core under pressure. At the beginning, the fiber paste was filled with half full or less. Some of the cable pastes were just applied to the outside of the cable core, and some were not filled at the ends of the fiber optic cable. This will make the optical fiber not well maintained, affect the transmission function of the optical fiber attenuation, and the waterproof function is not up to the national standard. Once the optical cable is not tested for water seepage, the entire link will seep and be scrapped. In the event of an abnormality, even if the seepage is not detected, only a section of the seepage can be repaired, and there is no need to start anew. (The national standard requires water blocking performance: three meters of fiber optic cable, one meter of water column pressure, no water seepage for 24 hours.) If you use poor ointment, the above problems will also occur, and may be due to poor thixotropy of the ointment. , The optical fiber will cause micro-bending consumption, and the transmission characteristics of all links are unqualified; if the grease is acidic, it will react with the metal materials in the optical cable to precipitate hydrogen molecules, and the attenuation of the optical fiber will increase rapidly when encountering H, causing the entire The link is interrupted for transmission.
2. Sheath. The fiber optic cable sheath must not only adapt to many different and complicated meteorological environments, but also ensure long-term stability (up to 25 years). The optical cable sheath must not only have a certain strength, low thermal deformation, abrasion, water permeability, thermal shrinkage and friction coefficient, but also have the characteristics of strong resistance to environmental stress and good material processing performance. Rarely used or poorly used sheathing materials may pass the factory acceptance, but due to quality defects, cracks and water seepage will appear after a period of application. If recycled plastics are used to replace high-quality polyethylene sheathing materials, it will be even more stressful. The fiber optic cable made of high-quality sheathing material has a flat, bright, uniform thickness and no bubbles after the cable is formed. Otherwise, the surface of the fiber optic cable will be rough, and because there are many impurities in the raw material, you can find that the outer skin of the fiber optic cable is very small. Wow, and because of its thin thickness, the overall outer diameter of the optical cable will be much smaller than that of a high-quality optical cable. Indoor optical cables are generally made of high-quality flame-retardant polyvinyl chloride. They should have a smooth, bright appearance, good flexibility, and easy peeling; otherwise, they will have poor skin finish and easily adhere to tight-fitting fibers and aramid.
3. Steel belt and aluminum belt. The steel strip and aluminum strip in the optical cable are mainly used to protect the optical fiber from the influence of the machine side pressure and moisture resistance. The chrome-plated steel strip is generally used in the better optical cable. Inferior fiber optic cables are made of ordinary iron sheet or black sheet (uncoated steel strip) with only one wall that has been treated for rust prevention. Instead of chrome-plated steel strip, rust will appear in the fiber optic cable when it is long, and the hydrogen loss of the fiber will also increase. And because it is easy to break up with the sheath, it cannot form a comprehensive bonding layer, and the moisture barrier function is also abnormally poor; some use tin-plated steel strips to replace chrome-plated steel strips. Prevented, so it is prone to corrosion under humid atmosphere and surface condensation or immersion conditions, especially under acidic conditions.
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