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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 identify abrupt changes in temperature at a given point. As an intruder walks in front of the sensor, the temperature at that point will rise from room temperature to body temperature and then back again. This quick change triggers the detection. PIR sensors designed to be wall- or ceiling-mounted come in various fields of view ...
While combining multiple sensing technologies into one detector can help reduce false triggering, it does so at the expense of reduced detection probabilities and increased vulnerability. [citation needed] For example, many dual-tech sensors combine both a PIR sensor and a microwave sensor into one unit. For motion to be detected, both sensors ...
1) "Strictly speaking, individual PIR sensors do not detect motion; rather, they detect abrupt changes in temperature at a given point using the Infrared radiation level" 2) "Moving objects of identical temperature, however, will trigger a detection because that is the sensor's job, to detect motion. It detects motion regardless of temperature.[4]
Remote photoelectric sensors used for remote sensing contain only the optical components of a sensor. The circuitry for power input, amplification, and output switching is located elsewhere, typically in a control panel. This allows the sensor, itself, to be very small. Also, the controls for the sensor are more accessible, since they may be ...
An induction or inductive loop is an electromagnetic communication or detection system which uses a moving magnet or an alternating current to induce an electric current in a nearby wire.
A piezoelectric sensor is a device that uses the piezoelectric effect to measure changes in pressure, acceleration, temperature, strain, or force by converting them to an electrical charge. The prefix piezo- is Greek for 'press' or 'squeeze'.
A Triggering device is an electronic circuit, ... Although it is always possible to control the amount of electrical power delivered to a load by using a variable ...