The vast majority of PID controllers in service today are digital in nature. Microprocessors executing PID…
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DC electric motors generate torque by a reaction between two magnetic fields: one field established by…
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Nearly every technical course teaches and tests students on definitions, basic concepts, and at least some…
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The following animation shows how the “rotating” magnetic field of a three-phase AC induction…
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Suppose we wished to measure the consumption of propane over time for a large propane storage tank supplying a…
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The fundamental principle of electromagnetism is that an electric current will create a magnetic field at…
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So far we have just looked at instruments that sense, control, and influence process variables. Transmitters,…
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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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A unique form of technical diagram for describing the abstract functions comprising a control system (e.g. PID…
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The electrical conductivity of liquids is an important analytical measurement in many industrial processes.…
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Most people reading this book have likely had the experience of adjusting water temperature using two hand…
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An important performance parameter for transmitter instruments is something often referred to as turndown or…
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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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Many years ago, when I was first learning about electricity, I happened to discover a length of coaxial…
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A sliding-stem valve body is one where the moving parts slide with a linear motion. Some examples of…
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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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One of the fundamental laws of electric circuits is Kirchhoff’s Current Law, which states the algebraic…
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A positive displacement flowmeter is a cyclic mechanism built to pass a fixed volume of fluid through with…
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A 4 to 20 mA current signal represents some signal along a 0 to 100 percent scale. Usually, this scale is…
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Cyber-security seems to have its own vocabulary, ranging from unwieldy technical acronyms to slang terms…
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