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gui chao cable news: how to identify the construction of security and shoddy cable?
from：guichao author：admin click： 450 addtime：2017-03-23 09:09:52
1, pvc sheath: the surface can be seen in the network inside the compression of the regular "roughness",
it shows that the processing technology is good, it will not produce relative sliding;
the appearance of smooth, can not see the compression of the network of "roughness", with the hand pinch jacket is loose dynamic, is poor cable.
2, check the shielding layer of the network: the number is enough, copper wire mesh, check solderability, tin plated copper wire inside is not copper,
the hardness of al mg alloy wire is obviously larger than that of copper wire, the network is sparse, the distribution is not uniform, and the insulation layer is not tight.
3, check the core line: diameter ---syv cable is 0.78 to 0.8mm, sywv cable is 1.0mm; recently appeared a syv75-5 core diameter is 1.0mm cable,
the characteristic impedance of the cable is certainly not 75 ohms and is not applied to a 75 ohm transmission system.
4, check the bonding force of the core and the insulation layer: inclined to cut the insulation layer, according to the direction of the peel off the core line, see the core line and the insulation layer has no bonding process materials;
a good cable has a large adhesive force, and the cable is not bonded.
longitudinal tensile test: take one meter cable, delamination core line, insulation, shielding, outer sheath, each 10 cm long.
the method is: two hands hold the adjacent two layers of the cable, pulling in the opposite direction; good cable general force pull, poor cable can not easily pull out.