How to identify the quality of weak current optical cables

Generally, the following seven factors are considered to measure the quality of optical cables: 1. Outer skin: Indoor optical cables are generally made of polyethylene or flame-retardant polyethylene, and the appearance should be smooth, bright, flexible and easy to peel off.

The skin finish of inferior optical cable is very poor, and it is easy to adhere to tight sleeves and aramid. The PE sheath of the outdoor optical cable should be made of high-quality black polyethylene, and the outer skin should be smooth, bright, uniform in thickness and free of bubbles. The skin of inferior optical cable is generally produced using ** material, the skin of this optical cable is rough, because there are many impurities in the raw materials, and a closer look can find that there are many very small pits in the outer skin of the optical cable, and it will crack and seep after laying for a period of time.

2. Optical fiber: regular optical cable manufacturers generally use the A-level fiber core of the large factory, and some low-cost and inferior optical cables usually use C-grade, D-class optical fiber and smuggled optical fibers from unknown sources, these optical fibers are complex and have a long factory time, and they often have been damp and discolored, and multi-mode optical fibers are often mixed with single-mode optical fibers, and the general small factories lack the necessary testing equipment to make a judgment on the quality of optical fibers. Because such optical fibers cannot be distinguished by the naked eye, the common problems encountered in construction are:

The bandwidth is very narrow and the transmission distance is short; The thickness is uneven, and it cannot be docked with the pigtail; The optical fiber lacks flexibility, and it breaks when the fiber is bent. 3. Strengthened steel wire: The steel wire of the outdoor optical cable of the regular manufacturer is phosphated, and the surface is gray, so that the steel wire does not increase hydrogen loss, does not rust, and has high strength.

Inferior fiber optic cables are generally replaced with thin iron or aluminum wires, and the identification method is easy - the appearance is white, and it can be bent at will when pinched in the hand. The fiber optic cable produced with such steel wire has a large hydrogen loss and a long time.

The two ends of the hanging fiber box will rust and break. 4. Steel armor: Regular production enterprises use longitudinal bandaging steel belts with double-sided brushing anti-rust coatings, and inferior optical cables are made of ordinary iron sheets, usually only one side has been treated with anti-rust.

5. Loose tube: The loose tube of the optical fiber installed in the optical cable should be made of PBT material, which has high strength, no deformation and anti-aging. Low-quality optical cables are usually made of PVC material to produce casings, which have a thin outer diameter and are flattened by hand, which is no different from beverage straws.

6. Fiber paste: The fiber paste in the outdoor fiber optic cable can prevent the fiber from oxidizing, due to the moisture entering the moisture, etc., there is very little fiber paste used in the inferior optical fiber, which seriously affects the life of the optical fiber. 7. Aramid:

Also known as Kevlar, it is a high-strength chemical fiber, which is currently the most used in the military industry, and military helmets and bulletproof vests are produced from this material. At present, only DuPont and Aksu in the Netherlands can produce it, which is about 300,000 tons. Indoor fiber optic cables and power overhead fiber optic cables (ADSS) are made of aramid yarn as reinforcements, because of the high cost of aramid, inferior indoor fiber optic cables generally make the outer diameter very fine, so that the cost can be saved by reducing a few strands of aramid, and such optical cables are easy to be pulled off when passing through the tube.

ADSS optical cable is based on the site span, wind speed per second to determine the number of aramid strands in the optical cable, must be carefully checked and confirmed before construction. The quality of the optical cable is directly related to the maintenance work in the later stage of the project, and the selection of the optical cable is the key.

1 Identification of the skin

Indoor fiber optic cables. Material: PVC flame retardant PVC.

Appearance: smooth, shiny, flexible, easy to peel.

Outdoor fiber optic cables. Material: PE sheath is made of high-quality black polyethylene.

Appearance: Flat and bright, uniform thickness, no bubbles.

2 Fiber Identification

Formal use of A-grade fiber core, inferior will use C or D grade fiber, and multi-mode fiber is often mixed with single-mode fiber.

Problems arise: narrow bandwidth, short transmission distance; uneven thickness can not be docked with pigtail; Lack of flexibility, the coil is easy to break.

3. Strengthen the identification of steel wires

Outdoor fiber optic cables. High quality: The steel wire is phosphated, the surface is gray--- the steel wire does not increase hydrogen loss after being cabled, does not rust, and has high strength.

Inferior quality: the use of general fine iron wire or aluminum wire, the appearance is white, can be bent at will--- the hydrogen loss of the optical cable is large, and the two ends of the optical fiber box will rust and break after a long time.

4 Steel Armor

High quality: longitudinal bandaging steel belt with anti-rust paint brushed on both sides.

Inferior quality: ordinary iron sheet, only one side of the anti-rust treatment.

5 Loosen the sleeve

High quality: using PBT material--- casing has high strength, no deformation, and anti-aging.

Inferior quality: PVC material, the outer diameter of the casing is very thin, and it is flattened when pinched.

6 Fiber paste

High quality: Outdoor fiber optic cable fiber paste prevents fiber oxidation and moisture.

Inferior quality: There is very little fiber paste, which affects the life of the optical fiber.

7 Kevlar (Kevlar, high-strength chemical fiber) - military industry: military helmets bulletproof vest material

Both indoor and power overhead cables (ADSS) are reinforced with aramid yarn (produced by DuPont and Aksuco in the Netherlands, more than 300,000 tons).

Inferior quality is generally very thin outer diameter--- easy to pull off.

Note: The ADSS optical cable is based on the site span and wind speed per second to determine the number of aramid strands used in the optical cable, and must be carefully checked and confirmed before construction.

How to judge the quality of the cable used in the weak current project, with the increase of the market, the products on the weak current have also appeared good and bad, so how to judge these fake copper wires and other related cables? For example, among them, the high imitation fake copper wire, which is a copper-clad aluminum-magnesium alloy in a certain proportion of multi-strand copper wires, similar counterfeit goods greatly affect the quality of our engineering posture.

The copper wire that does not meet the standard is not made of oxygen-free copper in the material, the transmission performance is not good, or the number of cores is not enough. The increasing number of counterfeit goods in the market has left consumers sad. For weak current cables, many businesses are selling under the banner of all-copper, but in fact, they are selling dog meat on the head of a sheep.

According to our understanding, the fake weak current cables on the market are divided into: general fake copper wires, high imitation fake copper wires, and substandard copper wires.

Generally, false copper wires include copper-clad aluminum, copper-clad aluminum, magnesium alloy, copper-clad steel, copper-clad iron, etc.; High imitation fake copper wire is a multi-strand copper wire with copper-clad aluminum-magnesium alloy in a certain proportion, and other materials are processed by electroplating copper.

Generally, ** is much more expensive than the previous one, after all, there is real copper in it; The copper wire that does not meet the standard is not made of oxygen-free copper in the material, the transmission performance is not good, or the number of cores is not enough. Opposite so many counterfeit cable products, in the process of selling weak current cables, whether it is online or under the inspection of wire ants, many customers will ask the question of identifying the quality of weak current cables, so how to distinguish it?

Identify the bad aspects of the cable

Sheath: The surface can see the regular "unevenness" of the net inside the compression, indicating that the processing technology is good, and there will be no relative sliding, which is a good cable. The appearance is smooth, and the "unevenness" of the compressed braiding mesh can not be seen, and the sheath is loose when pinched by hand, which is a poor cable;

Check the shielding layer netting: whether the number of weaving is enough for copper weaving, check the solderability, scrape the tinned copper wire to see if it is a copper wire, and the hardness of the aluminum-magnesium alloy wire is significantly greater than that of the copper wire; The network is sparse, unevenly distributed, and the insulation layer is not tightly wrapped.

Check the core: the diameter of the SYV cable is, the diameter of the SYWV cable is; Recently, there has been a kind of SYV75-5 core diameter cable, the characteristic impedance of this cable is certainly not 75 ohms, and it is not applied to 75 ohm transmission systems;

Check the adhesion force between the core wire and the insulating layer: cut the insulating layer obliquely, pull the core wire according to the peeling direction, and see if the core wire and the insulating layer are in touch with the process material; Good cables have a large sticking force, and poor cables do not have sticking;

Longitudinal tensile test: take a one-meter cable, peel off the core wire, insulation layer, shielding layer, and outer cover in layers, leaving 10 cm long each. Method:

Hold the two adjacent layers of the cable in both hands and pull them in opposite directions; Good cables can not be pulled by force, and poor cables can be easily pulled out without much effort - the elevator cable is very important, and many so-called "elevator special cables" have problems in this regard.

How to judge the quality of the cable used in weak current engineering, part of the knowledge mentioned above, we must pay attention to the standard when choosing the cable.

However, how to really get good performance and advanced products, we need to understand some basic identification means and methods. This article introduces some identification methods from the aspects of standards, physics, products, on-site testing and application of product performance and configuration, product materials and structure, international norms and production standards, etc., for netizens' reference. 1.

Looking at the appearance, the thickness of the outer diameter, of course the thick is good. 2.Look at the cable sheath.

The outer sheath of indoor optical cable is generally made of polygreen ethylene, or flame retardant polygreen ethylene, or low-smoke halogen-free materials. The high-quality appearance is smooth and shiny, and it feels good in the hand. It has good flexibility and is easy to peel.

The finish of the outer skin of the poor quality optical cable is not good, and when peeling off, the outer skin is easy to adhere to the tight sleeve and aramid inside, and it should be noted that some products use sponge instead of aramid material. The PE sheath of the outdoor optical cable should be made of high-quality black polyethylene, and the outer skin should be smooth, bright, uniform in thickness and without small bubbles. The skin of the poor quality optical cable has a poor feel, the outer skin is not smooth, and some printing is easy to be erased.

Due to the raw materials, some optical cable sheaths have poor density, and moisture is easy to penetrate. 3.View fiber cores.

The fiber core is the core part of the real optical cable, and the points mentioned above are more or less to protect the core of this transmission. At the same time, it is also the most difficult part to identify without the help of instruments. It is not possible to distinguish with the eye whether it is single-mode or multi-mode; It is also impossible to tell whether it is 50 125 or; You can't tell if it's OM1, OM2, OM3, or zero peak, let alone its Gigabit or 10 Gigabit applications.

It is best to recommend that you use high-quality fiber cores from regular large optical cable manufacturers. To be honest, some small factories cannot strictly inspect the fiber core due to their lack of necessary testing equipment. As a user, you don't have to take this risk to buy.

The problems often encountered in construction applications, such as insufficient bandwidth, inability to obtain calibration values for transmission distance, uneven thickness, difficult docking during splicing, lack of flexibility of optical fibers, and easy breakage during fiber coiling, are more or less related to the quality of optical fiber cores. 4.Please provide the test report of the optical fiber.

5.Use a gigabit fiber switch or fiber optic transceiver to verify that the fiber optic cable can reach gigabit. 6.

Product packaging. Optical cables are generally packed in wooden discs or iron and wood discs into shafts, and the outside of the discs will be sealed with wooden sealing plates to ensure that the stress, bending radius and other conditions of the bulky optical cable during the entire transportation are within the range of standard requirements. In order to save costs, inferior optical cables generally use very poor packaging trays, which are almost close to falling apart when they are transported to the destination.

The above talks about the basic means and methods of identification of some optical cable products, which are some empirical talks. In short, it is hoped that the majority of users of optical cable products can correctly understand optical fiber and cable products, check the factory information of optical cable products, pay attention to the structure and materials of products, adopt appropriate identification methods, rationally understand optical cable and performance quality, and be a rational consumer of optical fiber and cable products.

First, from the appearance. Communication fiber optic cables are almost the same, and it is difficult to judge from the appearance. There are ways to do it, though.

Generally speaking, the same type of communication optical cable, the outer diameter is thick, indicating that the sheath is made of more materials. The outer diameter of good or bad can be 2, in addition, the material used in the sheath, the high-quality sheath material is made of high-quality polyethylene or flame retardant material, and its outer skin is smooth and smooth, bright, uniform thickness, no bubbles, and easy to peel off. The optical cable made of recycled material and ** material often has a rough skin, and it can be found that there are many very small pits in the outer skin of the optical cable.

Second, judging from the internal structure of communication optical cables. The fiber core is the core raw material of communication optical cable, and it is the most important part that affects the quality of optical cable. Good communication optical cables generally use high-quality fiber cores, while inferior optical cables usually use low-level optical fibers, or even short-segmented optical fibers that come from the best to be spliced and then made into optical cables.

Third, the reinforcement is the main component of the cost of communication optical cable, is a high-strength chemical fiber, and the steel wire of the reinforcement is also very good. They are mainly used to protect optical fibers from mechanical pulling. A good fiber optic cable generally uses a high-modulus phosphated steel wire with a short-term tensile force of 1500N or 3000N.

Inferior optical cables will be replaced by iron wires or ordinary steel wires with small diameters, which are easy to rust on the one hand; On the other hand, since the tensile strength is much less than 1500N, the fiber may be strained during construction.

Fourth, another important point is ointment. Under normal circumstances, the paste should fill the entire loose tube, and the paste should fill every gap of the core of the optical cable under pressure. However, some inferior products are often filled with half full or less, and some of the cable paste is only smeared with a layer outside the cable core, and some are not filled in the middle of the two ends of the optical cable.