Inc. Purpose Occupancy sensors can reduce a building's lighting energy by turning lights off in unoccupied spaces. Energy savings may not be realized if the sensors are improperly installed or are disabled by dissatisfied occupants. For specifiers the task of identifying suitable products is complicated by the lack of standardized testing and reporting methods for occupancy sensors. Occupancy Sensors to explain the performance characteristics of occupancy sensors and to document their performance based on a method for objective evaluation of competing products. Technology Overview Infrared sensors.
Infrared sensors respond to the motion of a heat source, such as a person, within a space.
A segmented lens divides an infrared detector's field of view into zones. The unit detects motion when the heat source moves from one zone to another. The sensor must have a direct line of sight to the occupants to detect motion. Relatively small movements, such as typing on a keyboard, may not be sufficient to cross a zone and trigger the sensor. Ultrasonic sensors emit high-frequency waves in the range of 25 to 40 kilohertz, above the range of normal human hearing.