Motion Sensors Can Detect an Intruder

If you are shopping for home security, or upgrading an existing security system, it is helpful to understand how motion sensors work. Motion sensors are a standard part of many home security packages. Most motion sensors for home security are pyroelectric sensors, meaning they detect infrared energy. The sensors look like simple electronic components, but are sensitive to heat emitted from the human body. When a person walks through a room "guarded" by motion sensors, infrared energy is detected and an alarm is activated.