A passive infrared sensor (PIR sensor) is an electronic sensor that measures infrared (IR) light radiating from objects in its field of view. They are most often used in PIR-based motion detectors.
Read more about Passive Infrared Sensor: Operating Principles, Construction, PIR-based Motion Detector, PIR-based Remote Thermometer
Famous quotes containing the word passive:
“It is my conviction that in general women are more snobbish and class conscious than men and that these ignoble traits are a product of men’s attitude toward women and women’s passive acceptance of this attitude.”
—Mary Barnett Gilson (1877–?)