Advice Centre

CCTV Glossary

• Audio Monitoring: The ability to hear as well as see what is happening through your monitoring device.
  
  
• AV Channel: The channel on your TV that is usually used to watch DVDs and game consoles.
  
  
• BNC: A bayonet style connector for coaxial cable that is most commonly used for CCTV installations.
  
  
• CCD: ‘Charge Coupled Device’, which is used as a type of image sensor. CCD sensors are high quality sensors that are commonly used in portable camcorders and similar video equipment.
  
  
• CCTV: Closed Circuit Television. A television system used for private purposes and not for public or general broadcast.
  
  
• CMOS: Complimentary Metal Oxide Semiconductor, which is used in another type of image sensor. CMOS sensors are medium quality sensors that are commonly used in digital cameras and many low-powered image device such as USB webcams. See also CCD.
  
  
• Co-Axial Cable: This refers to cable that has a central conductor, surrounded by a shield sharing the same axis. The shield can be made from a variety of materials including, braided copper, or lapped foil. There are various standards for specific types of co-axial cable. The cable used for normal CCTV installations is called RG59.
  
  
• DIY Security: The component can easily be installed without the help of professional installers.
  
  
• DVR: Digital Video Recorder. This is a device that records video signal digitally. Normally this is on a large hard drive in the machine. For this reason it is sometimes known as a hard disk recorder (HDR).
  
  
• HDD: Hard Disk Drive.
  
  
• Image Sensor: The light sensitive chip inside a digital camera that can read levels of light & transform them into an image.
  
  
• Infra-red (IR): Infra-red Night Vision allows cameras to ‘see in the dark’. It is the method of using IR Light Emitting Diodes (LED) as illumination for a camera with a sensor that can ‘see’ infra-red light. Infra-red light provides the illumination needed to capture clear images in total darkness or low-light conditions.
  
  
• LCD Monitor: A monitor that uses liquid-crystal display technology. Many laptop and notebook computers use LCD displays because of their low power requirements. LUX: Unit of light measurement. 0.1 Lux (Full Moon) - 100,000 Lux (Direct Sunlight). The lower the number, the higher the sensitivity.
  
  
• Pan and Tilt: A motorised camera mounting that will move a camera both horizontally and vertically via electronic signals from a remote controller
  
  
• Quad Processor: A device used to display 4 cameras simultaneously on a single monitor.
  
  
• RCA AV Connector: A plug and socket for a two-wire (signal and ground) coaxial cable that is widely used to connect analogue audio and video.
  
  
• Resolution: Refers to the sharpness and clarity of an image.
  
  
• Television Lines (TVL): This is a measure of the resolution of a video device. Higher number is higher resolution. 380 TVL is considered medium resolution. 480 TVL or greater is considered high resolution.
  
  
• TFT Monitor: Stands for “Thin Film Transistor”. These transistors are used in high-quality flat panel liquid-crystal displays (LCD’s). TFT-based displays have a transistor for each pixel on the screen.
  
  
• Weather Resistant: Weather resistant cameras are able to be used in the outdoors if shielded from direct sun, rain, temperatures, snow and wind.
  
  
• Wireless - Transmission Distance: Outdoors - For open line of sight without obstruction approximately 330ft (100m). Indoors - Due to the many variables in building construction and other causes of interference, the useful range can vary but is usually between 66ft (20m) and 100ft (30m).