PIR technology senses occupancy by detecting the difference between heat emitted from the human body in motion and the background space. Relying on a clear line-of sight view, passive infrared sensors make 100% coverage cut off possible. These sensors utilize a unique fresnel lens which divides the coverage area into zone, enhancing detection of small movement. Using the doppler principle, ultrasonic sensors work by bouncing ultrasonic sound waves off objects in an area and measuring the time it takes for the waves to return. Movement by a person in the area causes the sound waves to return at a changed frequency, resulting in a doppler shift and occupancy detection.

WattStopper® Ceiling Mount Occupancy Sensor, Dual Technology Low Voltage, Series: DT Series, 24 VAC/VDC, 35 mA, Passive Infrared/Ultrasonic Sensor, 1000 sq-ft Coverage, 360 deg Viewing, 5 to 30 min Time Delay, LED Lamp, 40 kHz Response, Flying Lead Connection, Automatic On/Automatic Off Control Output, Ceiling/Swivel Bracket Mounting, 35 deg C, Plastic, White, 4.5 in Dia x 1.02 in D Dimensions

• 95% relative humidity, non-condensing, for indoor use only environmental conditions
• This dual technology ceiling sensor combines the benefits of passive infrared (PIR) and ultrasonic technologies to detect occupancy
• Sensors have a flat, unobtrusive appearance and provide 360 deg of coverage
• Detection signature analysis eliminates false triggers and provides immunity to RFI and EMI
• Walk through mode turns lights off 3 min after the area is initially occupied - ideal for brief visits such as mail delivery
• Sensors work with low voltage momentary switches for manual control
• 1 x 108 operating cycle
• Patented ultrasonic diffusion technology spreads coverage to a wider area
• Uses plug terminal wiring system for quick and easy installation
• Eight occupancy logic options provide the ability to customize control to meet application needs
• 1 A at 30 VAC/VDC load rating

• Specification Sheet https://11200from.stage.cimm2.com//ASSETS/DOCUMENTS/ITEMS/EN/IDW_DOCUMENT_4744536a98aae495bfa3ec49eff5f52336ba1aec94ec5e87d4824f18112d8074.pdf