How to distinguish the quality of optical fiber and cable

How to distinguish the quality of optical fiber and cable

1. Look at the paste, the paste is mainly fiber paste and cable paste, wire disc under normal conditions, fiber paste should be filled with all loose sleeve, cable paste should be filled under pressure cable core of every gap. Nowadays, the fiber paste is filled half full or less. Some cable paste is only applied with a layer outside the cable core, and some are filled at both ends of the cable without filling. This will make the fiber not good maintenance, affect the fiber attenuation and other transmission performance, waterproof function is not up to the national standards, once the cable accidentally seepage will cause the whole link seepage invalid. And under normal conditions, even if the accidental seepage also only need to repair the seepage of a section can be done, do not need to start over. If the same poor paste will appear above questions, and may be because of the poor thixotropy of the paste, will make the fiber into a micro bending loss, all link transmission characteristics are unqualified; If the acid of the paste belt will also react with the metal data in the cable to precipitate hydrogen molecules, and the optical fiber will rapidly increase in H attenuation, resulting in the suspension of transmission of all links.

2. Jacket, cable jacket not only to get used to a lot of different messy climate environment, but also to ensure long-term (at least 25 years) stability. Cable sheath should not only have a certain strength, low thermal deformation, wear, permeability, thermal retraction and friction coefficient, but also strong environmental stress resistance, good data processing function and other characteristics. Less use or use bad sheath material although can pass the factory inspection, but because of the quality of shortcomings after a period of time will appear cracking, seepage, if the replacement of high quality polyethylene sheath material with recycled plastic is more serious. High quality sheath material made of optical cable, cable after the skin is flat, light, uniform thickness, no bubbles, otherwise it will show the appearance of cable skin rough, and because the material has a lot of impurities, a closer look can be found that there are many very fine pit optical cable, and because the thickness is thin, all the outer diameter of the optical cable will be much smaller than the high quality optical cable. Indoor optical cable, usually choose high quality flame retardant PVC, the appearance should be lubricated, bright, good flexibility, easy to peel; Otherwise it will show poor skin finish, simple and tight sleeve fiber, aramid adhesion appearance.

3. Steel belt, aluminum belt, optical cable steel belt, aluminum belt is mainly used to maintain the optical fiber from mechanical side pressure, moisture-proof effect, etc., the best optical cable usually use chrome-plated steel belt. The residual optical cable to as long as one side of the rust disposal usually iron sheet or black (no coating steel belt), instead of chrome-plated steel belt, for a long time, the cable will appear rust, fiber hydrogen loss will also increase, and because it is easy to separate from the sheath structure does not induce bonding protective layer, damp function is also very poor; Some with tinned steel strip instead of chromium-plated steel strip, tinned steel strip appearance, bubbles, etc., is inevitable wire, so in moist atmosphere and appearance of condensation or immersion conditions, simple corrosion, especially under acidic conditions corrosion faster. Tin coating heat resistance is poor, melting point is only 232 degrees Celsius, in use because of the high temperature when the sheath is squeezed, the peeling strength is uncertain, affecting the anti-moisture function of the cable. The melting point of chromium is 1900 degrees Celsius, the chemical properties are very stable, at room temperature under the air or immersed in water will not rust, corrosion resistance function is very good, because the appearance is easy to oxidize the passivation layer so the environmental resistance function is excellent. Aluminum strip will usually appear to be unqualified hot coated aluminum strip instead of the ductile qualified coated aluminum strip, which will also affect the optical cable performance.

4. Steel wire, the steel wire in the optical cable is mainly used to maintain the optical fiber from mechanical tension. Good cables will usually use high modulus phosphating wire, short-term tension 1500N or 3000N. Defective cables are replaced with iron wire or steel wire of small diameter, which is easy to rust on the one hand; On the other hand, because the tensile strength is far less than 1500N, the fiber may be pulled during construction. High modulus phosphating wire is usually green gray, good endurance, not easy to zigzag; And the replacement of the wire is usually pinched in the hand can be arbitrary twists and turns for a long time, the two ends of the hanging fiber box will rust and crack.

5. The loose sleeve, the loose sleeve of the optical fiber in the optical cable usually uses polymer PBT data, the loose sleeve of the coil has high strength, no deformation, and anti-aging. The loose sleeve of the broken optical cable is sometimes replaced by other data. The outer diameter is very thin, and it is flat with a pinch of the hand. It is the same as a drink straw, which cannot bear the maintenance role of the optical fiber.

6. Waterproof belt, cable waterproof belt or waterproof yarn through the product is evenly distributed inside the high water absorption resin has a strong water absorption function, under the joint action of osmotic pressure, affinity, rubber elastic, high water absorption resin can quickly inhale several times its weight of water. Moreover, as soon as the powder meets water, it will immediately swell the gel, and no matter how much pressure is applied to it, the water will not be squeezed out. Therefore, the waterproof belt containing water absorbing resin is used to cover the cable core, and the outer wall of the cable is damaged. Some of the hyperabsorbent resin in the wound is swollen and sealed, which can prevent the entry of water to a minimum. Broken optical cable usually uses non-woven fabric or paper tape, once the cable skin is damaged, the results will be very serious.

7. Aramid, also known as Kevlar, is a high-strength chemical fiber that is most commonly used in the military industry. Bulletproof vests are produced from this material. Patented by DuPont, it is the primary capital component of indoor optical cables and is primarily used to maintain tight sleeve fibers in indoor optical cables from mechanical tension. But because of the high cost of arylon, the coil residual indoor cable usually makes the outer diameter very thin, which can be reduced by cutting a few strands of arylon section cost, or the use of a similar appearance of polyester yarn to replace arylon, and polyester yarn simply cannot accept what tension. In this way, the optical fiber is easily pulled or broken when laying.

8 optical fiber, optical fiber is the most central material in the optical cable, good optical fiber usually choose Dachang high quality fiber core. The incomplete optical cable is usually used in primary optical fiber and unknown private fiber, these optical fibers because of the origin of chaos, quality is difficult to ensure, sometimes multi-mode optical fiber is often mixed with single-mode optical fiber, and usually small factory lack of necessary inspection equipment, can not make discrimination on the quality of optical fiber, more make the quality is difficult to ensure. Others are being bought cheaply and spliced together to make cables later. Because the naked eye can not distinguish such fiber, the construction of the problem is often encountered: low transmission rate, short interval, fiber attenuation, can not dock with tail, lack of flexibility, disk fiber is easy to break, and even a fiber one end is multi-mode, the other end is single mode.

9. Coloring ink, in order to facilitate the construction of the optical fiber, the national requirements of the optical fiber and loose sleeve should be on the obvious color. High quality fiber optic cable according to the standard with high quality ink color, color is very obvious and not easy to drop. And the residual optical cable will use residual ink color or refreshing color. Incomplete ink color is not obvious and sometimes easy to dissolve in the fiber paste color can not be distinguished, color is not to bring great inconvenience to the construction.

10. Commodity packaging, optical cable is usually selected wood plate or iron wood plate shaft packaging, the outside of the plate will be sealed with wood plate, to ensure that the thick optical cable in all the transport force, tortuous radius and other conditions in the specification of demand scale. And the broken optical cable in order to save money, usually use very poor packaging plate, shipped to the destination is almost disassembled, wire some refreshing do not have to disk, the cable around the shipped, perhaps do not have to use the plate wooden seal.