Install them in restrooms to start, or install an entire facility and see the savings multiply. How Sensors Sense Occupancy Sensors use either acoustic, passive infrared, ultrasonic, or a combination of two technologies to detect occupancy.
Acoustic sensors use non-recording microphones that pick up sounds within a room.
The sensor detects sounds in the voice frequency range. Pairs with infrared. Infrared sensing relies on moving body heat. Ultrasonic sensors fill the room with high-frequency sound. Movement causes the reflected sound to have a frequency shift.