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Inductive Sensor
An inductive sensor is an electronic device that operates based on the principle of electromagnetic induction to detect or measure nearby metallic objects. An inductor develops a magnetic field when an electric current flows through it; alternatively, a current will flow through a circuit containing an inductor when the magnetic field through it changes. This effect can be used to detect metallic objects that interact with a magnetic field. Non-metallic substances, such as liquids or some kinds of dirt, do not interact with the magnetic field, so an inductive sensor can operate in wet or dirty conditions.Winncy Y. Du, ''Resistive, Capacitive, Inductive, and Magnetic Sensor Technologies'', CRC Press, 2014 , Chapter 4 ''Inductive Sensors'' Principle The inductive sensor is based on Faraday's law of induction. The temporal variations of the magnetic flux through a solenoid, coil with turns will induce a voltage which follows: : e = - N\frac which can be expressed in a simpler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proximity Sensor
A proximity sensor (often simply prox) is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an Electromagnetic field, electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the electric field, field or return signal. The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. For example, a capacitive proximity sensor or photoelectric sensor might be suitable for a plastic target; an inductive sensor, inductive proximity sensor always requires a metal target. Proximity sensors can have a high reliability and long functional life because of the absence of mechanical parts and lack of physical contact between the sensor and the sensed object. Proximity sensors are also used in machine vibration monitoring to measure the variation in distance between a shaft and its support beari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to form images of the organs in the body. MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from computed tomography (CT) and positron emission tomography (PET) scans. MRI is a medical application of nuclear magnetic resonance (NMR) which can also be used for imaging in other NMR applications, such as NMR spectroscopy. MRI is widely used in hospitals and clinics for medical diagnosis, staging and follow-up of disease. Compared to CT, MRI provides better contrast in images of soft tissues, e.g. in the brain or abdomen. However, it may be perceived as less comfortable by patients, due to the usually longer and louder measurements with the subject in a long, confining tube, although ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Flow Meter
{{Short description, Device for measuring flow of a fluid A ''magnetic flow meter'' (mag meter, electromagnetic flow meter) is a transducer that measures fluid flow by the voltage induced across the liquid by its flow through a magnetic field. A magnetic field is applied to the metering tube, which results in a potential difference proportional to the flow velocity perpendicular to the flux lines. The physical principle at work is electromagnetic induction. The magnetic flow meter requires a conducting fluid, for example, water that contains ions, and an electrical insulating pipe surface, for example, a rubber-lined steel tube. If the magnetic field direction were constant, electrochemistry, electrochemical and other effects at the electrodes would make the potential difference difficult to distinguish from the fluid flow induced potential difference. To show this in modern magnetic flowmeters, the magnetic field is constantly reversed, cancelling out the electrochemical potent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Variable Differential Transformer
The linear variable differential transformer (LVDT) – also called linear variable displacement transformer, linear variable displacement transducer, or simply differential transformer – is a type of electrical transformer used for measuring linear displacement (position along a given direction). It is the base of LVDT-type Displacement sensor, displacement sensors. A counterpart to this device that is used for measuring rotary displacement is called a ''rotary variable differential transformer'' (RVDT). Introduction LVDTs are robust, absolute linear position/displacement transducers; inherently frictionless, they have a virtually infinite cycle life when properly used. As AC operated LVDTs do not contain any electronics, they can be designed to operate at cryogenic temperatures or up to 1200 °F (650 °C), in harsh environments, and under high vibration and shock levels. LVDTs have been widely used in applications such as Turbine, power turbines, hydraulics, auto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Sensors
This is a list of sensors sorted by sensor type. Acoustic, sound, vibration * Acoustic radiometer *Geophone *Hydrophone *Microphone * Pickup *Seismometer * Sound locator Automotive *Air flow meter * Air–fuel ratio meter *Blind spot monitor * Crankshaft position sensor (CKP) *Curb feeler *Defect detector * Engine coolant temperature sensor *Hall effect sensor *Wheel speed sensor *Airbag sensors * Automatic transmission speed sensor *Brake fluid pressure sensor * Camshaft position sensor (CMP) * Cylinder Head Temperature gauge * Engine crankcase pressure sensor * Exhaust gas temperature sensor * Fuel level sensor * Fuel pressure sensor *Knock sensor *Light sensor *MAP sensor * Mass airflow sensor *Oil level sensor * Oil pressure sensor *Omniview technology *Oxygen sensor (O2) *Parking sensor *Radar gun * Radar sensor *Speed sensor * Throttle position sensor * Tire pressure sensor *Torque sensor * Transmission fluid temperature sensor * Turbine speed sensor * Variable relucta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Magnetic Resonance
Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are disturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a frequency characteristic of the magnetic field at the nucleus. This process occurs near resonance, when the oscillation frequency matches the intrinsic frequency of the nuclei, which depends on the strength of the static magnetic field, the chemical environment, and the magnetic properties of the isotope involved; in practical applications with static magnetic fields up to ca. 20 tesla, the frequency is similar to VHF and UHF television broadcasts (60–1000 MHz). NMR results from specific magnetic properties of certain atomic nuclei. High-resolution nuclear magnetic resonance spectroscopy is widely used to determine the structure of organic molecules in solution and study molecular physics and crystals as well as non-crysta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiofrequency Coil
Radiofrequency coils (RF coils) are the receivers, and sometimes also the transmitters, of radiofrequency (RF) signals in equipment used in magnetic resonance imaging (MRI). The MR signal in MRI is produced by the process of resonance, which is the result of radiofrequency pulses. They consist of two electromagnetic coils, the transmitter and receiver, which generate the field and receive the resulting signal. Atomic nuclei of interest in MRI studies have their own resonant frequencies, in the radiofrequency portion of the electromagnetic spectrum. Although the electromagnetic fields produced by the transmitting coil are in the RF range of tens of megahertz (often in the shortwave radio portion of the electromagnetic spectrum) at powers usually exceeding the highest powers used by amateur radio, there is very little RF interference produced by the MRI machine. The reason for this is that the MRI is a poor radio transmitter and lacks an antenna. The RF frequency electromagnetic fiel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induction Loop
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. Induction loops are used for transmission and reception of communication signals, or for detection of metal objects in metal detectors or vehicle presence indicators. A common modern use for induction loops is to provide hearing assistance to hearing-aid users. Applications Vehicle detection Vehicle detection loops, called ''inductive-loop traffic detectors'', can detect vehicles passing or arriving at a certain point, for instance approaching a traffic light or in motorway traffic. An insulated, electrically conducting loop is installed in the pavement. The electronics unit applies alternating current electrical energy onto the wire loops at frequencies between 10 k Hz to 200 kHz, depending on the model. The inductive-loop system behaves as a tuned electrical circuit in which t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Car Wash
A car wash, or auto wash, is a facility used to clean the exterior, and in some cases the interior, of motor vehicle, cars. Car washes can be #Self-serve car wash, self-service, full-service (with attendants who wash the vehicle), or #Automatic car wash, fully automated (possibly connected to a filling station). Car washes may also be events where people pay to have their cars washed by volunteers, often using less specialized equipment, as a fundraiser. History The first U.S. patent for a mechanized car wash was filed in 1900 and soon followed by "auto laundries". The Automobile Laundry in Detroit, Michigan, opened in 1914 by Frank McCormick and J.W. Hinkle, is considered the first business in the U.S. to adopt the name "car wash" for their services. Manual car wash operations, which used manpower to push or move the cars through stages, peaked at 32 drive-through facilities in the United States. The first semi-automatic car wash in the United States debuted in 1946 at a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traffic Light
Traffic lights, traffic signals, or stoplights – also known as robots in South Africa, Zambia, and Namibia – are signaling devices positioned at intersection (road), road intersections, pedestrian crossings, and other locations in order to control the flow of traffic. Traffic lights usually consist of three signals, transmitting meaningful information to road users through colours and symbols, including arrows and bicycles. The usual traffic light colours are red to stop traffic, Amber (color), amber for traffic change, and green to allow traffic to proceed. These are arranged vertically or horizontally in that order. Although this is internationally standardised, variations in traffic light sequences and laws exist on national and local scales. Traffic lights were first introduced in December 1868 on Parliament Square in London to reduce the need for police officers to control traffic. Since then, electricity and computerised control have advanced traffic light technolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal Detector
A metal detector is an instrument that detects the nearby presence of metal. Metal detectors are useful for finding metal objects on the surface, underground, and under water. A metal detector consists of a control box, an adjustable shaft, and a variable-shaped pickup coil. When the coil nears metal, the control box signals its presence with a tone, numerical reading, light, or needle movement. Signal intensity typically increases with proximity and/or metal size/composition. A common type are stationary "walk through" metal detectors used at access points in prisons, courthouses, airports and psychiatric hospitals to detect concealed metal weapons on a person's body. The simplest form of a metal detector consists of an oscillator producing an alternating current that passes through a coil producing an alternating magnetic field. If a piece of electrically conductive metal is close to the coil, eddy currents will be induced ( inductive sensor) in the metal, and this produces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
