Occupancy Sensor
From Swikipedia
Introduction
Occupancy sensors are sensing devices commonly connected to a room’s lighting but also occasionally to heating or ventilation, which shut down these services when the space is unoccupied.
Brief Description
The placement and orientation of occupancy sensors should be appropriate, also considering the furniture placement in the room. Occupancy sensors must be able to sense all occupants to avoid turning off lights while the space is occupied. At the same time, the sensitivity of the sensors must be set to avoid "false-on" incidents triggered by passersby in adjoining hallways. Occupancy sensors with their sensitivity set too high can fail to save energy, and occupancy sensors with too low a sensitivity or too short a delay time can be annoying to occupants.
Types of Occupancy Sensors:
Infrared Occupancy Sensor: They detect temperature changes in a room and perform better where the entire room is within the sensor’s field of view.
Ultrasonic Occupancy Sensor: They use high frequency sound to detect motion even around corners.
Dual Technology Sensors: They use both infrared and ultrasonic methods, increasing accuracy and flexibility, but are available at a higher cost.
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