An occupancy sensor is a device that is used to detect the presence of people in a particular area. It is often used to control lighting, HVAC (heating, ventilation, and air conditioning) systems, and other building systems in order to improve energy efficiency and comfort.
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There are several types of occupancy sensors, including passive infrared (PIR) sensors, ultrasonic sensors, and microwave sensors. PIR sensors detect changes in infrared radiation (heat) and are commonly used in residential and commercial settings. Ultrasonic sensors use sound waves to detect movement and are often used in office buildings and other large spaces. Microwave sensors use microwaves to detect movement and are often used in outdoor settings.
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Occupancy sensors can be programmed to turn off lights and other systems when an area is not in use, and to turn them on when someone enters the area. This helps to reduce energy consumption and save money on utility bills. Occupancy sensors are also useful for security purposes, as they can be used to trigger alarms or other alerts if someone enters an unauthorized area.