Learn How to Choose the Right Type of Motion Sensors

Posted by Dave VanTol on Tue, May 31, 2011 @ 15:05 PM

Infrared, Ultrasonic, Dual Technology, which do I choose?


In a previous post "Motion Sensors 101", I listed the functions of motion sensors.

I am going to discuss the different technologies and what applications they are best suited.


(PIR) or infrared sensors are activated by the movement of a persons body heat through a zone. The style commonly used mounts in a normal switch box and usually replaces a standard light switch.

This type of sensor is best used in small enclosed spaces such as a private office. Typically no extra wiring is needed. The down side of PIR sensors is they cannot see through windows, walls, or partitions. Occupants must be in direct site.


Ultrasonic sensors operate on a similar principle to radar. Low frequency sound patterns are sent out from the sensor into an area, moving objects altering the signal activate the sensor.

These are best suited where there isn't always a line of site of the room occupants. A typical application for this type of sensor is restrooms. The hard surfaces make minor motion detection much easier.

Dual Technology:

Dual technology sensors use....well you guessed it, both types of technologies. This type of sensor virtually reduces any false triggering when no one is in the space.

The minor drawback to this type of technology is that it does cost slightly more.

Motion Sensors and Energy Efficiency:

Motion sensors are a perfect fit for energy efficiency applications.  It only makes sense to turn the lights off in an area that is not occupied at the time.

Learn More?

Want to learn more about energy efficiency and how motion sensors can help your business?

Download our FREE Guide:Business Owners Guide to Energy Efficiency to learn about how energy efficiency can make your business more profitable.

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photo source drillspot.com

Topics: motion sensor, occupancy sensor, ultrasonic, motion