Why is the security monitoring video cable 75 ohms?
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In order to minimize crosstalk and external interference between cable loops, shielding is employed. The type of shielding used depends on the application environment and can include individual twisted-pair shielding, overall twisted-pair shielding, or a combination of both. These methods help ensure signal integrity and reduce electromagnetic interference.
Shielding materials commonly used are round copper wires, copper tapes, and aluminum-plastic composite tapes. These materials offer excellent insulation properties and maintain high performance even under varying conditions. If a potential difference occurs between the shield and the conductors during operation, it does not affect the quality of signal transmission, ensuring reliable performance in critical applications.
This product is ideal for use in electronic computers and automatic connection cables with a rated voltage of 500V or lower. The ground core insulation utilizes K-type B low-density polyethylene, which has antioxidant properties. This material provides high insulation resistance, excellent dielectric strength, a low dielectric constant, and minimal dielectric loss, making it suitable for long-term use and ensuring the cable's durability and performance.
**Technical Parameters:**
- Rated Voltage (U0/U): 300/500V
- Long-term Operating Temperature: 70°C
- Ambient Temperature During Installation: -40°C for fixed laying, -15°C for non-fixed laying
- Minimum Bending Radius: Non-armored cables should be at least 6 times the outer diameter, armored cables at least 12 times
- Insulation Resistance: At 20°C, after 500V DC testing, it should be no less than 1 MΩ·km
- Dielectric Strength Test: 50Hz for 5 minutes, with a voltage not exceeding 5000V between cores and shields
- **AC Rated Voltage:** U0/U = 300/500kV
- **Maximum Working Temperature:**
- Polyethylene insulation: ≤70°C
- Cross-linked polyethylene: ≤90°C
- Low-smoke halogen-free polyolefin: ≤70°C
- Low-smoke halogen-free cross-linked polyolefin: ≤90°C and 125°C
- Polyfluoroethylene (F46): ≤200°C
- Imported soluble PFA: ≤260°C
- **Minimum Ambient Temperature:**
- PVC sheath: -40°C (fixed), -15°C (non-fixed)
- Fluorine plastic and silicone rubber sheath: -60°C (fixed), -25°C (non-fixed)
- **Installation Temperature:** Not below 0°C (high-temperature type: not below -25°C)
- **Bending Radius:** Non-armored cables: 6x outer diameter; copper tape or steel-armored cables: 12x outer diameter
**Product Usage:**
This cable features low capacitance, low inductance, and superior shielding and anti-interference capabilities. The special high-temperature computer cable uses imported fluorine plastic and fluorine rubber, allowing it to operate continuously in environments ranging from -40°C to 260°C. It is non-flammable, resistant to acids, alkalis, oil, and water, and is designed for safe, explosion-proof circuits. It can be installed on cable trays, in trenches, or directly buried. This high-temperature intrinsically safe computer cable was awarded a national patent in 2000. It is ideal for use in explosive protection systems, harsh environments, and automated detection systems, offering significantly better explosion-proof performance compared to standard DCS and computer control cables.