Closed Circuit TV
CCTV systems on their own should never be regarded as a complete solution to a security problem. They should be seen as one of a series of measures which when combined will make premises, be it commercial or domestic, more secure.
Camera types
CCTV cameras come in many shapes and sizes dependant on the application. Modern cameras provide a high quality colour image which when the light quality (Lux level) falls will give a black and white (monochrome) image. Fully functional cameras have the facility to pan tilt and zoom and can be controlled remotely either from the site or by an Alarm Receiving Centre (ARC) (see monitored systems below).
CCTV systems fall into four main categories.
Observation systems
Consist of cameras linked to a CCTV monitor used mainly to check entrances to view callers. Normally fitted in conjunction with an access control system.
Recorded systems
Any number of cameras viewing perceived vulnerable areas linked to a CCTV Monitor and a digital video recorder. The recorder will store images from all the cameras for up to 30 days and if required the cameras can be viewed remotely via the internet using the recorder’s on board ethernet link. These systems are referred to as passive in that they record events as they occur but do not generate any reaction.
Monitored systems
Cameras linked to a monitor, digital recorder and a telephone link to an Alarm Receiving Centre (ARC). Activation of the system is generated by externally fitted movement sensors or infra red beams. Staff at the ARC can remotely monitor the cameras and verbally speak to the site using voice informers and issue warnings. If the system by design complies with British Standard 8418 then a police response can be generated.
Covert systems
Cameras can be concealed in all sorts of everyday items such as clocks, electrical junction boxes, movement sensors and smoke detectors to name a few. The cameras are linked as above to recorders.
General
Lighting levels are vital for ensuring good quality images and so a site visit is essential for designing a CCTV system. Light levels can be enhanced by white light, infra red light and thermal imaging. Number plate details are often required these can be achieved using specialist number plate recognition cameras. Facial recognition of individuals can be achieved only if the subject gets close to the camera and is not masked.
Data Protection Act
Some larger CCTV systems have to be registered with the Information Comissioners Office. Notes of guidance are issued with each specification.