The acronym CCTV stands for Closed Circuit Television. Few will realize that this is a CCTV by name only. Even after translating these words into Russian (closed-circuit television), it is not clear what kind of system it is and what it is intended for. Let's see what CCTV is, what its purpose and application is. Let's start with the banal.
CCTV - what is it
This is a system that includes video cameras, a hardware-technical complex, monitors, recorders, lenses, as well as various elements for signal amplification. The main objective of this system is to monitor at local, local, remote sites. Most trading floors, warehouses and enterprises are equipped with a similar video surveillance system, which allows you to monitor the actions of workers and visitors, monitor staff activities and generally ensure the normal functioning of the enterprise and protection against crime. These are the main functions of the system.
Purpose of CCTV
Using this system you can:
- Monitor the situation at a specific facility.
- Receive information directly at the post in real time.
- Ensure the fixation of video and audio using a digital recorder.
- Receive video confirmation of violation at the facility.
- Implement the alarm function, which will be based on the operation of camera motion detectors or sensors.
Perhaps now you understand that this is a CCTV. The system can be considered in more detail.
CCTV Security Cameras
The most popular cameras in the security market are models created on the basis of CCD-matrices. The largest manufacturers of such cameras are well-known brands: Samsung, LG, Panasonic, Sony. Moreover, they offer both cheap economy-class cameras and expensive high-quality equipment with wide functionality and increased reliability.
According to the design characteristics of CCTV cameras can be divided into several types:
- Modular. These are frameless devices that are installed in hemispheres or thermocases. They are so called because They don’t have their own corps.
- Miniature. These cameras in small cases are usually square or cylindrical, used for internal video surveillance, but it is extremely rare to find models with protective cases for outdoor use.
- Dome. They are used indoors and are usually attached to the ceiling or to other horizontal surfaces using a special bracket.
- Case. These cameras are designed for video surveillance in any conditions and rooms. They can be used outdoors or in buildings, regardless of their affiliation. Note that if case cameras are used outdoors, they must have special thermal housings that protect the device from frost and water and dust. All this can damage electronic components, so thermal shrouds are required. Otherwise, even the case camera will not last long.
- Outdoor cameras. If any camera is installed in a thermal case with the lens heating function, then it already belongs to this class. It is easy to guess that they are intended for organizing outdoor surveillance.
- Rotary speed. This class includes cameras with a rotary mechanism and zoom. Note that the potential of these cameras in comparison with others is greater, therefore they are often used to implement effective CCTV systems.
- Hydrostabilized camcorders. These have special video stabilization systems, so they can be used on moving objects.
In addition, analog or digital (known as IP cameras) models can be used to organize the CCTV system. A similar division can be made by considering the design of the device itself. For example, cameras can be wired or wireless. The latter have a high-frequency antenna as a transmitting device. It can also be a Wi-Fi interface.
Recorders
In order to finally understand that this is CCTV, it is necessary to consider video recording devices as the main elements of the system along with cameras. We are talking about digital video recorders that record video and audio to a hard drive or other drive. All of them are divided into three categories:
- Video servers are devices that are organized on a simple computer running Linux or Windows using a video capture card and programs for processing and recording video. If we are talking about organizing the protection of a very large enterprise, then for this purpose they specially assemble a computer, which subsequently becomes the core of the security system.
- Non-computer recorders such as non-PC, DVR, Stand-alone.
- Specialized registrars. These are systems that can include various components designed to solve specific problems. For example, there are registrars designed to record and store video received from cameras of a video surveillance system, which is organized in subway cars. An explosion-proof memory may be used.
Image processing devices
No CCTV system can be implemented without this element. The image from the camera should be transmitted to one monitor. For this, switches or video switches are most often used. When it is necessary to transfer several images from different cameras to one monitor, resort to the use of a quad.
A more complex device is a multiplexer. It allows you to organize the simultaneous display of images obtained from different cameras, and broadcast on the monitor screen. Also with its help it is possible to form a sequential change of images from all cameras for recording purposes.
Types of Lenses
We have already figured out in sufficient detail that this is a CCTV. But the final point can be put after considering the types of lenses. When organizing this system, the following lenses can be used:
- Monofocal with a constant focal length that does not change.
- Varifocal lenses in which the focal length can be changed manually.
- Zoom Here the focal length can be changed manually or automatically.
Changing this parameter allows you to zoom in or out of the image, which to some extent provides increased reliability.
Conclusion
Now you know that this is CCTV, what is the purpose of this system and its main components. If earlier this system was a rarity, today it is implemented even in the largest retail outlets. This is a fairly flexible system, which can cost millions of rubles, or it can cost only 5-10 thousand, but its main task is to organize video surveillance of the object. Given the flexibility and diversity of its constituent elements, there is no specific CCTV instruction, as for each object, it will be individual, taking into account the cameras used, image processing and recording devices.