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De-mining (the detection of landmines), the detection of weapons such as knives and guns (particularly in airport security), geophysical prospecting, archaeology, and treasure hunting are just some of the applications. Metal detectors are also used to detect foreign bodies in food, as well as steel reinforcement bars in concrete and pipes.
A motion detector attached to an outdoor, automatic light. A motion detector is an electrical device that utilizes a sensor to detect nearby motion (motion detection).Such a device is often integrated as a component of a system that automatically performs a task or alerts a user of motion in an area.
Speed sensors are machines used to detect the speed of an object, usually a transport vehicle. They include: Wheel speed sensors; Speedometers; Pitometer logs; Pitot tubes; Airspeed indicators; Piezo sensors (e.g. in a road surface) LIDAR; Ground speed radar; Doppler radar; ANPR (where vehicles are timed over a fixed distance)
The device that performed this function in the receiver circuit was called a detector. [1] A variety of different detector devices, such as the coherer, electrolytic detector, magnetic detector and the crystal detector, were used during the wireless telegraphy era until superseded by vacuum tube technology.
Newer speed detection devices use pulsed laser light, commonly referred to as LIDAR, rather than radio waves. Radar detectors, which detect radio transmissions, are unable to detect the infrared light emitted by LIDAR guns, so a different type of device called a LIDAR detector is required. However, LIDAR detection is not nearly as effective as ...
The Spectre III detected almost every radar detector certified for operation in the United States by the Federal Communications Commission as of December 2004. However counter technology has evolved rapidly, so that by July 2008, even budget radar detectors were able to avoid detection by the device. [ 2 ]
The materials basis for infrared detection devices are narrow-gap semiconductors, including compounds and alloys of bismuth, antimony, indium, cadmium, selenium and others. [3] [4] Lead(II) sulfide (PbS) Mercury cadmium telluride (Known as MCT, HgCdTe) Indium antimonide (InSb) Indium arsenide; Indium gallium arsenide; Lead selenide; QWIP ...
Incident light causes a change in the base current, which controls the transistor's collector current. Phototransistors offer amplification and can be used in applications that require both detection and signal amplification. Charge-Coupled Devices (CCDs): CCDs are imaging sensors composed of an array of tiny capacitors. Incident light ...