The quality of the transmitted signal and the bandwidth of the communication line are very important when installing video surveillance systems. Therefore, experts choose the installation of fiber-optic cable among other cable systems. It is much longer without additional reinforcement, high reliability and protection from electromagnetic interference. All these features have made optical lines much more popular in the installation of cable communication systems.
Installation of optical cable is a time consuming process. If we talk about a video surveillance system, the first role is important cable bandwidth (the amount of information transmitted per unit time), which affects the image quality. The fact is that the soldering of fiber optic cable, and installation, as well as the design of fiber-optic communication lines require high skills and experience from a specialist. All this determines the cost of welding fiber and other work on laying fiber optic cable.
For all work to be performed at the highest level, it is desirable to understand the basic concepts in the installation of fiber optics. This will make it easier for you to assess the expertise of potential contractors and be confident in the quality of the work done.
Fiber optic communication line
Fiber-optic communication lines refers to the technology of laying a fiber-optic cable designed to carry information in the optical range. It is currently considered the most modern type of data transmission.
Fiber optics is a technology that uses light as a carrier, and the type of signal being transmitted does not matter (it can be digital or analog). Due to the design of fiberglass and its transparency, the signal can quickly travel long distances.
The cable consists of thin fiberglass (approximately 1-10 μm in diameter) and internal insulation (glass or plastic). The signal is transmitted on the principle of complete internal reflection of light from the boundary of two substances with different refractive indices. Sometimes the fiber may have a metal braid. In fact, it does not require any shielding from external electromagnetic interference, but as a method of mechanical protection from the environment it is sometimes used.
There are several types of fiber optic cables:
Multimode (cheaper, but worse quality). Due to the successive achievement of the receiver, the signal shape is distorted. For this reason, it is used for systems with a short length (up to 1 km). The advantage of this option is low cost, the usual LED, which increases the service life of the receiver. If we talk about signal delay, it is approximately similar to electrical cords. Therefore, multimode cable is more common and affordable.
Single-mode (more expensive, has a higher quality). If you need to connect over long distances up to hundreds of kilometers, you will need to buy a single-mode cable. In this case, all the rays reach the receiver at the same time, which means that the signal is practically not distorted. Its main advantages - low variance, data transmission over long distances.
Why the installation of fiber optic cable is a priority?
The first thing you need to know is that fiber is more expensive than other materials. It is more difficult to lay it, because such work requires both qualifications and expensive equipment. But the quality of fiber optic cable is much better than copper and especially copper plating (aluminum with a copper coating). Indeed, fiber-optic communication lines have many advantages over other methods of transmitting information. The most important are the following characteristics:
High protection against interference, because light as a signal carrier remains completely inside the fiber optic cable and does not provoke external electromagnetic radiation;
Security and confidentiality of transmitted information, which is especially important for video surveillance (you can connect to such a cable only if its integrity is violated);
The potential bandwidth reaches 1012 Hz, which means much more than electrical networks;
High fire safety if the chemical and physical parameters of the environment change.
Of course, fiber is not perfect and has its drawbacks. Problem # 1 - difficult installation. The master requires micron precision, the ability to work with expensive equipment (for example, to create a chip, the accuracy of which depends on the attenuation in the connector). Another number of disadvantages - less flexibility and strength than the electric cable, as well as sensitivity to ionizing radiation, temperature changes, mechanical effects. Therefore, manufacturers have now begun to offer customers fiber optics with a durable glass shell.
Fiber optic cable installation:
1 Design of fiber-optic communication lines. The specialist must personally visit the site, clarify all important data, agree on the method of fiber-optic cable routing with the client. Do not do without the development and maintenance of project documentation.
2 Laying of a fiber optic cable. This is the longest and most responsible process that begins with preparation. You will need special tools to work:
2.1 cleaver - a device that is designed to obtain a flat and perpendicular to the fiber surface of the chip. To do this, it is wiped with ethanol, fixed in the device, and the knife in the equipment makes a microscopic incision on the cable and due to small efforts it splits in the right place.
2.2 welding machine - a device whose task is to splice the fiber. This is especially common if the line is long or if the cable consists of several segments. To do this, the chipped fibers are fixed, then the welding machine delivers a short discharge at the end of the fiber to get rid of dust. After that, the device reduces the fibers for welding the optical cable in three coordinates with increasing accuracy. The last task of the welding machine is to evaluate the quality of work for strength, damping. Next, the master takes out the fiber and the coupling to close the welding site, and then puts everything in the shrinkage furnace and at the end of the required time waits for complete cooling.
2.3 optical coupler or crossover, designed to connect the optical cable and connect the necessary equipment to it;
2.4 ethanol and wipes for cleaning;
2.5 stripper tool if you need to strip the fiber.
3 Testing. Preliminary control after installation of a fiber-optic cable helps to prevent shortcomings and to correct them in time, and means guarantees correct work of the equipment. Special control and measuring devices are required for testing:
3.1 visual flaw detector (its task is to detect external damage in the optical fiber and software, to determine the quality of soldering of the optical cable);
3.2 optical reflectometer (able to determine the causes of the fault and provide all the information about the communication lines).
3.3 partition for fiber tracing (determines the presence of a signal);
3.4 optical power meters (necessary for adjusting the level of laser radiation of equipment, power testing in certain areas of the network);
3.5 optical spectrum analyzers (help in setting up and optimizing data transmission systems);
3.6 fiber optic breakers, radiation detectors and other devices.
If you are working on fiber optic cable yourself, then remember the safety precautions. It is important to follow the established rules when welding the fiber optic cable and its installation: work with clean hands in a room with low dust content, do not touch the cleaned optical fiber with your fingers. Even small chipped parts of the optical fiber can be dangerous: if they get under the skin, they will be a rolling pin, and if you try to get them, they will start to crumble; if they get into food or water - there is a risk of damaging the walls of the esophagus or intestines. Be sure to prepare a container for the remnants of fiber and collect them there.
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