The transformer is one of the most important components in all of AC circuitry. Principally used to…
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One of the fundamental laws of electric circuits is Kirchhoff’s Current Law, which states the algebraic…
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Since we often use electricity to convey energy from one location to another, it is important to be able to…
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While 50 and 51 (instantaneous and time overcurrent) relay functions monitor line current magnitude and guard…
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The term “grid” refers to the conductors and equipment interconnecting power sources to power…
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By definition, a source is a device delivering energy into a system, while a load is a device extracting…
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DC electric motors generate torque by a reaction between two magnetic fields: one field established by…
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The two “process variables” we rely on most heavily in the field of electrical measurement and…
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Current is the name we give to the motion of electric charges from a point of high potential to a point of low…
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Those familiar with industrial instrumentation will find much within the electric power industry remarkably…
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Circuit breakers used in residential, commercial, and light industrial service are self-tripping devices: they…
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Three-phase AC is the dominant mode of electric power generation and distribution in modern societies.…
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In the United States, the ANSI and IEEE organizations have standardized a set of numerical codes referring to…
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A form of protection against faults on long-distance power lines is called distance relaying, so named because…
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“Polyphase” means “many phases,” describing a form of AC electrical system where…
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Disconnect Switches Disconnects are switches designed to isolate sections of a power system in case of damage…
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Electrical power grids primarily consist of three-phase AC circuits. This means most power lines (transmission…
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Weight-based level instruments sense process level in a vessel by directly measuring the weight of the vessel.…
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A variety of problem-solving techniques have been presented for students over the years which are all helpful…
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DC electric motors generate torque by a reaction between two magnetic fields: one field established by…
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Learning from reading printed text is a kind of problem-solving activity it is own right. The problem is how…
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In order to provide an interface between the internal (digital) world of a computer and the external (analog)…
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Modern analog-to-digital converters are phenomenally accurate, dependable, repeatable, and surprisingly…
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Lipták, Béla G. et al., Instrument Engineers’ Handbook – Process Measurement and Analysis Volume I,…
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At the next OSI Reference Model layer (layer 4) is a set of protocols specifying how reliable communication…
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Binary patterns are not just able to represent numerical values. Given a standardized code, they may represent…
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I remember first learning about the world-wide Internet, and wondering what it actually looked like. The first…
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Visualizing the actions of P, I, and D tuning parameters using graphs is extremely useful in predicting the…
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An important design parameter of a control valve is the position it will “fail” to if it loses…
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The following animation shows the calculus concepts of differentiation and integration (with respect to time)…
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“As to methods there may be a million and then some, but principles are few. The man who grasps…
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There is much to be said for neatness of assembly in electrical signal wiring. Even though the electrons…
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The simplest form of 4-20 mA current loop is the type used to represent the output of a process controller,…
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A technological advance introduced in the late 1980’s was HART, an acronym standing for Highway…
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Coy, John J. et. al. (December 2012) Sampled graphic illustrations from his NASA Reference Publication…
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One of the great benefits of digital technology is the ability to communicate vast amounts of information over…
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Mechanical pressure-sensing elements include the bellows, the diaphragm, and the bourdon tube. Each of these…
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The three “elementary” particles of matter comprising all atoms are electrons, protons, and…
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Perhaps the most important rule to obey when using pneumatic instruments is to maintain clean and dry…
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One very convenient feature of waves is that their properties are universal. Waves of water in the ocean,…
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A wise PLC programmer once told me that the first thing any aspiring programmer should learn about the PLC…
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Valves can experience a number of problems, most of them either preventable or repairable. These problems can…
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The two “process variables” we rely on most heavily in the field of electrical measurement and…
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Steam boilers are very common in industry, principally because steam power is so useful. Common uses for steam…
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To review, voltage is the measure of potential energy available to electric charges. Current is the uniform…
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Regulating the electric power sent to an electric motor is a task performed by high-speed switching…
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Calculus has a reputation for being difficult to learn, and with good reason. The traditional approach to…
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In reliability engineering, it is important to be able to quantity the reliability (or conversely, the…
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A completely different way of measuring liquid level in vessels is to bounce a traveling wave off the surface…
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As we have seen, feedforward control is a way to improve the stability of a feedback control system in the…
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A very common form of on/off valve used for pneumatic and hydraulic systems alike is the solenoid valve. A…
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Perhaps the most valuable skill an instrument technician can possess is the ability to efficiently diagnose…
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As we have seen, the concept of integration is finding the accumulation of one variable multiplied by another…
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This section does not describe a particular type of flowmeter, but rather a design that may be implemented for…
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Measuring the flow rate of liquid through an open channel is not unlike measuring the flow rate of a liquid…
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Suppose we wished to measure the rate of propane gas flow through a hose to a torch: Flowmeters appropriate…
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A vertical column of fluid generates a pressure at the bottom of the column owing to the action of gravity on…
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