1) Copper: High-quality cable uses high-purity oxygen-free copper. The copper core is bright and the surface of the poor copper wire is dim.
2) Plastic: The plastic uses high-quality virgin plastic, which has good bending performance. The cable will not be textured when bent, and the poor recycled plastic will have obvious texture after bending for several times.
3) The foot: Copper is a precious metal. If the copper diameter is deficient, it can reduce the cost of raw materials. In this case, the micrometer should be used to measure the diameter of the copper wire. If you don't have a micrometer, the easier way is to take a full coil of wire and see if it is much lighter than a good cable. Or you can refer to the nominal weight given by the factory. Some factories give a low nominal weight, which naturally does not guarantee product quality.
4) Foot meter: It may be more difficult to detect the number of hands on the meter, because the customer generally does not have the equipment to actually measure the meter number. The same weight measurement method can be used to know whether the cable is full. Or it is a good way to print the meter when the factory is produced, but be aware that there is no way to print the meter with a diameter of less than 5mm.
5) Accessories: In order to ensure the rounding of the cable, for the multi-core cable, the filler will be added to the core, and the thickness of the sheath will be thicker. If the cable is not round, the filler is added. Rarely, and the sheath is thin.
6) bundle wire: multi-strand copper wire will be bundled at the time of production to improve the tensile strength, roundness, electrical properties and tightness of the copper core, but the wire will increase the amount of copper used. Therefore, many factories have omitted this step. The method of resolution is to cut through the core of the cable and see if the copper wires inside are regularly twisted together.
7) Weaving: A cable with a copper mesh braid, the braid occupies a large part of the cost of the cable material, and the coverage of the braid directly affects the electrical performance of the cable. At the same time, the tight braid can increase the strength of the cable. Reduce the electrical performance degradation of the cable in the bent state. Therefore, it is an important means to distinguish the advantages and disadvantages of the cable.
8) Foaming: Some cables need to foam the insulating layer to enhance its electrical properties. The foaming mainly consists of chemical foaming and physical foaming. The chemical does not require special production equipment, so the price is low, but the bubbles produced vary in size. , electrical performance is poor. Physical foaming requires expensive production equipment, but the bubbles produced are uniform and fine, and the bending is small, the attenuation is small, and the electrical properties are excellent. Such a cable core wire can be cut to see if its foamed layer is uniformly and finely bubbled.
2. The importance of the foot and the foot:
The high cost of raw materials for cables and the excessive competition in the domestic market have led many manufacturers to use the raw materials of cables, but this can lead to very serious consequences.
1) If the copper wire is made thin, it will cause the conductor resistance to become large, generate heat, cause heat, and even cause fire.
2) The use of poor cable material in the insulation layer will result in poor heat resistance and premature aging. If it is a soft wire, it will cause multiple bending and rupture, which may cause electric shock.
3) If the jacket layer is too thin, the durability will be reduced. It should be noted that the cable is generally used for more than 10 years.
4) Other craftsmanship cuts can lead to a serious drop in the transmission bandwidth and distance of the signal line.