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Displacement Sensor
Displacement measurement is the measurement of changes in directed distance (displacement). Devices measuring displacement are based on displacement sensors, which can be contacting or non-contacting. Some displacement sensors are based on displacement transducers, devices which convert displacement into another form of energy. Displacement sensors can be used to indirectly measure a number of other quantities, including deformation, distortion, thermal expansion, thickness (normally through the combination of two sensors), vibration, spindle motion, fluid level, strain and mechanical shock. Displacement sensors exist that can measure displacement on the order of nanometers or smaller. Application Displacement receivers can be used to study and observe the stress waves passing through a material after it is struck.Hsu, K., Cheng, C., Hsu, S., & Yu, P. (2022)Rapid assessment of fire damage to reinforced concrete structures using the surface wave method with contact and non-co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Displacement (geometry)
In geometry and mechanics, a displacement is a vector whose length is the shortest distance from the initial to the final position of a point P undergoing motion. It quantifies both the distance and direction of the net or total motion along a straight line from the initial position to the final position of the point trajectory. A displacement may be identified with the translation that maps the initial position to the final position. Displacement is the shift in location when an object in motion changes from one position to another. For motion over a given interval of time, the displacement divided by the length of the time interval defines the average velocity (a vector), whose magnitude is the average speed (a scalar quantity). Formulation A displacement may be formulated as a '' relative position'' (resulting from the motion), that is, as the final position of a point relative to its initial position . The corresponding displacement vector can be defined as the diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GlobalSpec
GlobalSpec is a technology services company which provides a search engine of engineering and industrial products, indexing over 180 million parts divided into 2,300,000 product families, from over 24,000 manufacturer and distributor catalogs. GlobalSpec is a domain-specific (or "vertical search") tool, in that its focused domain allows for optimized results. Within product families, searches can be narrowed by selecting values for parameters that are specific to that product type. The website has over 8 million registered members, and as of 2009, membership was growing at a rate of 20,000 per week. In 2007, the company achieved 35% revenue growth, the sixth year in a row that the company achieved double-digit revenue growth. The website has approximately 1.3 unique million visitors a month with 2.8 million page views and an average of 4.9 minutes time spent. GlobalSpec has partnerships with several well-known companies, including: * AltaVista * The International Society of Aut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphonic
Polyphony ( ) is a type of musical texture consisting of two or more simultaneous lines of independent melody, as opposed to a musical texture with just one voice ( monophony) or a texture with one dominant melodic voice accompanied by chords ( homophony). Within the context of the Western musical tradition, the term ''polyphony'' is usually used to refer to music of the late Middle Ages and Renaissance. Baroque forms such as fugue, which might be called polyphonic, are usually described instead as contrapuntal. Also, as opposed to the ''species'' terminology of counterpoint, polyphony was generally either "pitch-against-pitch" / "point-against-point" or "sustained-pitch" in one part with melismas of varying lengths in another. In all cases the conception was probably what Margaret Bent (1999) calls "dyadic counterpoint", with each part being written generally against one other part, with all parts modified if needed in the end. This point-against-point conception is oppose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musical Keyboard
A musical keyboard is the set of adjacent depressible levers or keys on a musical instrument. Keyboards typically contain keys for playing the twelve notes of the Western musical scale, with a combination of larger, longer keys and smaller, shorter keys that repeats at the interval of an octave. Pressing a key on the keyboard makes the instrument produce sounds—either by mechanically striking a string or tine ( acoustic and electric piano, clavichord), plucking a string (harpsichord), causing air to flow through a pipe organ, striking a bell (carillon), or activating an electronic circuit (synthesizer, digital piano, electronic keyboard). Since the most commonly encountered keyboard instrument is the piano, the keyboard layout is often referred to as the piano keyboard or simply piano keys. Description The twelve notes of the Western musical scale are laid out with the lowest note on the left. The longer keys (for the seven "natural" notes of the C major scale: C, D, E, F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipe Organ
The pipe organ is a musical instrument that produces sound by driving pressurised air (called ''wind'') through the organ pipes selected from a Musical keyboard, keyboard. Because each pipe produces a single tone and pitch, the pipes are provided in sets called ''ranks'', each of which has a common timbre, volume, and construction throughout the keyboard Compass (music), compass. Most organs have many ranks of pipes of differing pitch, timbre, and volume that the player can employ singly or in combination through the use of controls called Organ stop, stops. A pipe organ has one or more keyboards (called ''Manual (music), manuals'') played by the hands, and most have a Pedal keyboard, pedal clavier played by the feet; each keyboard controls its own division (group of stops). The keyboard(s), pedalboard, and stops are housed in the organ's Organ console, ''console''. The organ's continuous supply of wind allows it to sustain notes for as long as the corresponding keys are pressed, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tracker Action
Tracker action is a term used in reference to pipe organs and steam calliopes to indicate a mechanical linkage between keys or pedals pressed by the organist and the valve that allows air to flow into pipe(s) of the corresponding note. This is in contrast to " direct electric action" and " electro-pneumatic action", which connect the key to the valve through an electrical link or an electrically assisted pneumatic system respectively, or " tubular-pneumatic action" which utilizes a change of pressure within lead tubing which connects the key to the valve pneumatic. History Ancient history Organs trace their history as far back as at least the 3rd century BC with an organlike device known as the hydraulis. Also known as a "water organ" or "Roman organ", the hydraulis was an instrument in which water was used as a source of power to push wind through organ pipes. (It is not to be confused with the hydraulic action of a hydraulophone, an instrument that actually uses water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strain Gauges
A strain gauge (also spelled strain gage) is a device used to measure strain on an object. Invented by Edward E. Simmons and Arthur C. Ruge in 1938, the most common type of strain gauge consists of an insulating flexible backing which supports a metallic foil pattern. The gauge is attached to the object by a suitable adhesive, such as cyanoacrylate. As the object is deformed, the foil is deformed, causing its electrical resistance to change. This resistance change, usually measured using a Wheatstone bridge, is related to the strain by the quantity known as the gauge factor. History Edward E. Simmons and Professor Arthur C. Ruge independently invented the strain gauge. Simmons was involved in a research project by Dätwyler and Clark at Caltech between 1936 and 1938. They researched the stress-strain behavior of metals under shock loads. Simmons came up with an original way to measure the force introduced into the sample by equipping a dynamometer with fine resistance wir ... [...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] |
Reinforced Concrete
Reinforced concrete, also called ferroconcrete or ferro-concrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (known as rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials. In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion. Description Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transducer
A transducer is a device that Energy transformation, converts energy from one form to another. Usually a transducer converts a signal in one form of energy to a signal in another. Transducers are often employed at the boundaries of automation, Measuring instrument, measurement, and control systems, where electrical signals are converted to and from other physical quantities (energy, force, torque, light, motion, position, etc.). The process of converting one form of energy to another is known as transduction. Types * Mechanical transducers convert physical quantities into mechanical outputs or vice versa; * Electrical transducers convert physical quantities into electrical outputs or signals. Examples of these are: ** a thermocouple that changes temperature differences into a small voltage; ** a linear variable differential transformer (LVDT), used to measure displacement (position) changes by means of electrical signals. Sensors, actuators and transceivers Transducers can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stress Wave
Linear elasticity is a mathematical model of how solid objects deformation (physics), deform and become internally stress (mechanics), stressed by prescribed loading conditions. It is a simplification of the more general Finite strain theory, nonlinear theory of elasticity and a branch of continuum mechanics. The fundamental assumptions of linear elasticity are Infinitesimal strain theory, infinitesimal strains — meaning, "small" deformations — and linear relationships between the components of stress and strain — hence the "linear" in its name. Linear elasticity is valid only for stress states that do not produce Yield (engineering), yielding. Its assumptions are reasonable for many engineering materials and engineering design scenarios. Linear elasticity is therefore used extensively in structural analysis and engineering design, often with the aid of finite element analysis. Mathematical formulation Equations governing a linear elastic boundary value proble ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanometre
330px, Different lengths as in respect to the Molecule">molecular scale. The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm), or nanometer (American spelling), is a unit of length in the International System of Units (SI), equal to one billionth ( short scale) or one thousand million (long scale) of a meter (0.000000001 m) and to 1000 picometres. One nanometre can be expressed in scientific notation as 1 × 10−9 m and as m. History The nanometre was formerly known as the "''millimicrometre''" – or, more commonly, the "''millimicron''" for short – since it is of a micrometer. It was often denoted by the symbol ''mμ'' or, more rarely, as ''μμ'' (however, ''μμ'' should refer to a ''millionth'' of a micron). Etymology The name combines the SI prefix '' nano-'' (from the Ancient Greek , ', "dwarf") with the parent unit name ''metre'' (from Greek , ', "unit of measurement"). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
