Philips OccuSwitch Ceiling Mount Multi-Tech 500 sq. ft. Motion Sensor

Philips OccuSwitch Classic multi-tech sensors are the most advanced sensors available because they combine multi-technology sensing with all digital architecture. They are designed to help eliminate false triggering, resulting in trouble-free lighting control. These sensors realize the benefits of both Infrared and Ultrasonic technologies for their performance and reliability. Ultrasonic (Doppler shift) motion detection provides maximum sensitivity yet can be vulnerable to false triggering from air conditioning currents, corridor activity and movement of inanimate objects. Infrared motion sensing gives immunity to false triggering, but lacks sensitivity at greater distances. Upon room entry, the infrared detects motion and turns the lights on. Ultrasonic sensors keep the lights on even when very minor motion is detected. When unoccupied, lights stay off while air conditioning system cycles on and off, and cleaning crews occupy corridors.