Nowadays, most network cameras installed still use twisted pair (network cable) transmission, and the commonly used ones are Category 5e and Category 6 cables. If the 100M network is used, we usually use Category 5e twisted pair, and the Gigabit network uses Category 6 twisted pair.
[Twisted pair wire diameter]
Let’s talk about the national standard Category 5e and Category 6 wire diameters here, because there are various wire diameters of network cables on the market, and there are also many non-standard ones. The national standard Category 5e wire diameter is 0.5, and the national standard Category 6 wire diameter is 0.56. Theoretically, the thicker the wire diameter, the longer the transmission distance, but the transmission distance is also closely related to the material of the network cable.
[Twisted pair material]
Common materials on the market: alloy; high-conductivity aluminum; high-conductivity silver; pure copper; oxygen-free copper.
1. Alloy: The lowest price is iron, but the quality is also the worst.
2. High conductivity aluminum: commonly known as copper-clad aluminum, it is mainly made of aluminum and is easily oxidized. After oxidation, the resistance will increase. This is why copper-clad aluminum network cables are used to install monitoring equipment. There will be no problems when it is newly installed, but after a period of time, there will be problems with intermittent signals.
3. High-conductivity silver: High-conductivity silver is also made of aluminum, and its quality is better than copper-clad aluminum. This is how it is called. There is no silver in the material.
4. Pure copper material: The quality is better than that of aluminum, but the resistance is still relatively large.
5. Oxygen-free copper: Also known as red copper, it is currently the best network cable according to the national standard. It is recommended that everyone try to choose this kind of network cable for monitoring.
[Twisted pair selection]
In addition to buying a better brand and a higher price, if you encounter a merchant who is unkind, you should also be able to test it yourself. The commonly used detection method is to measure resistance with a multimeter.
A box of network cables is normally 300 meters (actually about 305 meters). Test the resistance of the whole box. The resistance value of Category 5e should be about 27-30 ohms, and the resistance value of Category 6 cables should be about 21-24 ohms.
The reliable transmission distance of network cable is about 100 meters. Never hear on the Internet that others transmit 120 meters, and 150 meters is no problem. The signal will attenuate over the distance transmitted by the network cable, and data packets will be lost.
