How do you monitor the cable so much?

According to national standards, the cable cost is generally about 2.25 yuan / meter, and some engineering companies blindly pursue low prices, cable suppliers in order to meet the low price psychology of the engineering firm, change the various methods to produce the line of cut corners cable. Therefore, the current cable quality is much worse than before. Here are some simple ways to check the cable quality.

Identification method

1, check the shielding layer network: whether the number is enough? Copper wire mesh, check the solderability, tinned copper computer wire scrape to see if it is inside the copper wire, the hardness of the aluminum-magnesium alloy wire is significantly larger than the copper wire; The distribution is not uniform, and the insulation layer is not tightly wrapped, etc. It is a poor cable; if it is a copper-clad aluminum, it is easy to see that the internal color is different from the copper outside; peeling off the outer skin, see If the braiding angle of the shielding layer is basically upright, it can be basically seen that the knitting angle is large, which is a product for cutting corners;

2, PVC sheath: the surface can be seen to press the inside of the net has a regular "unevenness", indicating that the processing technology is good, will not produce relative sliding, is a good cable. The appearance is smooth, and the "unevenness" of the compacted net is not seen. The hand-pinched jacket has a loose feeling, which is a poor cable;

3. Check the adhesion between the core wire and the insulation layer: cut the insulation layer obliquely, and pull the core wire in the peeling direction to see if the core wire and the insulation layer are in contact with the process material; the cable has a large adhesion force and difference. The cable is not glued;

4, check the core wire: diameter - SYV cable is 0.78-0.8mm, SYWV cable is 1.0mm; recently appeared a SYV75-5 core wire diameter of 1.0mm cable, the characteristic impedance of this cable, certainly not 75 Ohm, not applied to a 75 ohm transmission system; use a vernier caliper to check the diameter of the cable core;

5, longitudinal tensile test: take a meter of security cable, layered stripping core wire, insulation layer, shielding layer, outer casing, each leaving 10 cm long. The method is: two hands respectively hold the adjacent two layers of the cable and pull in the opposite direction; the good cable generally pulls the power, and the difference cable can be easily pulled out without much effort.

6. Open a roll of wire to measure the length, or use the method of weighing to judge;

solution

If you have purchased the above unqualified cable and have a problem, here are a few recommended solutions:

1. If the transmission distance exceeds 800 meters, use SYV-75-5 cable, and find that no image or image is beating, you can use video amplification anti-dry rao device, which uses video segmentation amplification method, can enlarge the video signal 10 Times, this can effectively extend the transmission distance (can not use a simple amplifier, otherwise the signal loss is very large);

2. If several cables interfere with each other, multi-signal multiplexing equipment can be used, and 8 video images and control signals can be simultaneously transmitted in one video cable;

3, if you encounter the problem of cable welding, it is recommended to buy pure tin welding wire, and use high-power soldering iron for rapid welding, must not slowly tin;

4. Finally, if the video cable is not safe, you can also use RF cable to transmit multiple video signals. One RF cable can transmit 20 channels of images and control signals at the same time. The transmission range is up to 3 kilometers, so the cost will be more cost-effective.

Conclusion

In general, cable fraud is also caused by the lower profits of the engineering company, and everyone wants to buy lower products to get more profits. On the one hand, engineering companies should open their eyes and carefully identify the advantages and disadvantages of cables. On the other hand, it is possible to adopt new technologies to reduce costs. This will enable enterprises to gain advantages in the fierce competition in which raw materials are rising sharply and labor costs are increasing rapidly.