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The technology typically found in motion sensors to trigger an alarm includes infrared, ultrasonic, vibration and contact. Dual technology sensors combine two or more forms of detection in order to reduce false alarms as each method has its advantages and disadvantages. Traditionally motion sensors are an integral part of a home security system.
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 ...
1. Unfamiliar people on the street. Burglars often case several homes at the same time, especially if they’re on a single street. They learn very quickly which homes have people coming and going ...
An optical sensor converts light rays into electronic signals. It measures the physical quantity of light and then translates it into a form readable by an instrument. An optical sensor is generally part of a larger system that integrates a source of light, a measuring device, and the optical sensor. This is often connected to an electrical ...
Photodetectors may be used in different configurations. Single sensors may detect overall light levels. A 1-D array of photodetectors, as in a spectrophotometer or a Line scanner, may be used to measure the distribution of light along a line. A 2-D array of photodetectors may be used as an image sensor to form images from the pattern of light ...
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.
Ambient light falling on the photoresistor causes the streetlight to turn off. Thus energy is saved by ensuring the light is only on during hours of darkness. Photoresistors are also used in laser-based security systems to detect the change in the light intensity when a person or object passes through the laser beam.
A suspect dubbed the “snake burglar” by police has been successfully evading motion-triggered alarms in Riverside, California, and made off with $8,000 from a hair salon’s safe, along with ...