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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. PIR sensors are commonly used in security alarms and automatic lighting applications. PIR sensors detect general movement, but do not give ...
Infrared signature, as used by defense scientists and the military, is the appearance of objects to infrared sensors. [1] An infrared signature depends on many factors, including the shape and size of the object, [2] temperature, [3] and emissivity, reflection of external sources (earthshine, sunshine, skyshine) from the object's surface, [4] the background against which it is viewed [5] and ...
A camera trap with a passive infrared (PIR) sensor. A camera trap is a camera that is automatically triggered by motion in its vicinity, like the presence of an animal or a human being. It is typically equipped with a motion sensor – usually a passive infrared (PIR) sensor or an active infrared (AIR) sensor using an infrared light beam.
Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or functional groups in solid, liquid, or gaseous forms. It can be used to characterize new materials or identify ...
Security lighting to prevent intrusions may be counter-productive. Turning off lights halved the number of thefts and burglary in Övertorneå Sweden. [2] [3] A test in West Sussex UK showed that adding all-night lighting in some areas made people there feel safer, although crime rates increased 55% in those areas compared to control areas and to the county as a whole.
Contradiction - black body radiation. All objects emit what is known as black body radiation. This energy is invisible to the human eye but can be detected by electronic devices designed for such a purpose. The term passive in this instance means that the PIR sensor does not emit energy of any type but merely passively accepts incoming infrared ...
Security alarm. A security alarm is a system designed to detect intrusions, such as unauthorized entry, into a building or other areas, such as a home or school. Security alarms protect against burglary (theft) or property damage, as well as against intruders. Examples include personal systems, neighborhood security alerts, car alarms, and ...
An occupancy sensor is an indoor device used to detect the presence of a person. Applications include automatic adjustment of lights or temperature or ventilation systems in response to the quantity of people present. The sensors typically use infrared, ultrasonic, microwave, or other technology. The term encompasses devices as different as PIR ...