Mon, 11 Dec, 2017

CCTV

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CCTV Guide - Compare CCTV (closed circuit television) products and services.

CCTV means television for a fixed number of private viewers. Mostly used for security purposes. There is now a huge range of CCTV products available on the market, covering a wide range of different applications. CCTV prices obviously vary considerably.

 

Traditionally only sturdy industrial CCTV systems were available at high cost, however technology has now enabled smaller, simpler CCTV cameras to be manufactured at much more affordable prices.

 

There are two main types of CCTV cameras Ė CMOS (Complementary Metal Oxide Semiconductor ) and CCD (Charge-coupled device). Though it is not important to understand the complex technology behind these cameras, the difference between the two is significant. Generally CCD cameras have higher resolution, therefore offer more clarity. Though they are more expensive, you should opt for a CCTV camera with a CCD chipset in practically every situation. Make sure the cameras you are looking at specify the type of chipset.

 

Main considerations:

 

1. Resolution

Make sure your camera has a resolution over 350 TVL. Above 500 TVL will enable you to read the number plate of a moving car.

 

2. Sensitivity

Ask yourself what light levels will the CCTV camera be required to operate in. Light levels are calibrated in LUX. The amount of light energy landing on one square metre is measured in LUX i.e. full daylight is 50,000 lux whereas dawn or dusk is around 5 lux. Donít worry about a camera having to deal with too much light; the problems happen when it cannot cope with the low light. Make sure the CCTV system can deal with at least ten times its minimum scene illumination.

 

3. Indoor/outdoor application

If the CCTV camera is going to be mounted outdoors, it either needs to be enclosed or it needs to be completely water-resistant. Check sealing around the leads, often this is an area that is not dealt with effectively by the CCTV manufacturers. Make sure the casings are robust and do not buy an outdoor CCTV unit with a thin plastic outer casing.

 

4. Mutiplexors / Recorders

Do you need multiple cameras? If so you may need a multiplexor. These take pictures from each camera and feed them into the video recorder. It can also display the separate videos from a single split screen. They should allow for the separate playback from each camera at a later stage. Most new recorders are now DVRs or Digital Video Recorders and come already fitted with multiplexors and motion detectors.