If you need security and surveillance coverage in poorly lit or no light areas, you should try using an infrared camera system. In the following article we'll talk about how these cameras work and what to look (out) for when purchasing a system.
The motion sensor itself is an infrared sensor. In fact, the name of the sensor is a Passive InfraRed or PIR detector. It works by constantly monitoring the infrared radiation (IR) in the cameras general field of view. When a sudden change in this radiation occurs, the sensor can detect it, and assumes it is caused by an object in motion. The PIR motion sensor is connected to a relay switch so that when motion is connected, the relay switch turns on the camera to being recording. The recording session ends when either the motion has stopped or after a pre-programmed period of time after the motion has stopped.