When detecting motion, it is usually measuring by the changes in speed or vector of an object in the field of view. The motion can be detected by sound, opacity, geomagnetism, reflection of transmitted energy, electromagnetic induction and vibration. And all the motion is connected to the motion sensor, or occupancy sensor. It is a device that turns light and other equipment on or off in response to the presence of people in a defined area. A complete sensor is composed of a motion sensor, an electronic control unit, and a controllable switch. Sometimes a timer may also be included to signals the electronic control unit after a set period of inactivity.
Most of the occupancy sensors are designed to control the light depending on the amount of daylight in the coverage area. Now, more complicated sensor units can offer a variety of adjustment capabilities. Besides, there are also some occupancy sensors designed for small areas like bathrooms, stairwells and hallways. This kind of sensors are generally inexpensive and effective devices that can be installed on a wall or ceiling without any extra effort. And here are some tips for purchasing an occupancy sensor for small areas. The coverage area is not as important as the feature requirements. The things you have to pay attention to are the compatibility, failure mode, indicators, manual controls, minimum load, timer settings, coverage and warranty.
