1. how to distinguish the advantages and disadvantages of the cable:
1) high quality copper cable with high purity oxygen free copper, bright copper core and poor copper wire surface.
2) plastic and plastic use high quality primary plastic, good bending performance, bending of cable will not produce texture, poor recycled plastic will appear obvious texture after a few times bending, bending many times after breaking up.
3) foot cupric copper is a kind of precious metal. If the diameter of copper is less than one point, it can reduce a large amount of raw material cost. In this way, the diameter of copper wire is measured with a micrometer. If there is no micrometer, the simpler way is to take the whole volume.
The wire is weighed to see if it is much lighter than the quality cable. Or may refer to the nominal weight given by the factory. The nominal weight of some factories is too low to guarantee the quality of products.
4) the feet of feet may be more difficult to detect on the meters, because the customers generally have no equipment to measure the number of meters, and the same weight measurement method can be used to know whether the cable is full of rice. Or let the factory mark the meter when it is produced.
A good method, but pay attention to the diameter of less than 5mm line is no way to mark the rice.
5) in order to ensure the roundness of the cable, the multi core cable will add the filler in the core, and the thickness of the sheath is thicker. If the cable is not round, it shows that the filler is added very little, and the sheath is done.
6) the bundle wire will be made in the production of the wire to improve the tensile properties, the roundness, the electrical properties and the tightness of the insulating layer. However, because the wire will increase the use of copper, many factories have omitted this.
One way to do that is to cut the core of the cable and see if the copper wire is regularly stranded together.
6) weave the cable with the braid layer of the copper net. The braiding layer accounts for a large part of the cost of the cable material, and the coverage rate of the braided layer directly affects the electrical performance of the cable. At the same time, the strength of the cable can be increased by the compact braiding layer.
The electrical performance of the cable is reduced under the bending condition. Therefore, to see whether the braided layer has high coverage rate and uniform weave is an important way to distinguish the advantages and disadvantages of the cable.
7) foaming some cables need to foam insulation to enhance their electrical properties, foams mainly have chemical foaming and physical foaming, chemistry does not require special production equipment, so the price is low, but the size of the bubbles is different and the electrical property is produced.
It can be bad. Physical foaming requires expensive production equipment, but the resulting bubbles are uniform and dense, with little attenuation under bending and good electrical properties. The cable core can be cut open to observe whether the foam layer is even.
Fine and dense.
The importance of 2. feet meter feet:
The cost of the raw materials of the cable is very high, and the excessive competition in the domestic market has caused many manufacturers to move their hands and feet on the raw materials of cable, but this may lead to very serious consequences.
1) transmission of electric cables, if the copper wire is thin, will cause the conductor resistance to become larger, generate heat, cause fever, and even cause a fire.
2) the use of poor cable material in the insulating layer will lead to poor heat resistance and premature aging. If it is a soft wire, it will lead to multiple bending and rupture, causing an electric shock hazard.
3) the sheathing layer is too thin, which will result in a decrease in durability. It is generally known that cables should be used for more than 10 years.
4) Jerry building on other technologies can lead to a serious decline in the transmission bandwidth and distance of signal lines.