In the United States, the ANSI and IEEE organizations have standardized a set of numerical codes referring to…
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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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Creative Commons Attribution 4.0 International Public License By exercising the Licensed Rights (defined…
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All masses require force to accelerate (we can also think of this in terms of the mass generating a reaction…
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The digital multimeter (DMM) is quite possibly the most useful tool in the instrument technician’s…
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The reason why a pneumatic control valve’s stem position corresponds linearly to the amount of air…
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“Polyphase” means “many phases,” describing a form of AC electrical system where…
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There are several different methods useful for causing an AC induction motor to brake, or slow down: DC…
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The two “process variables” we rely on most heavily in the field of electrical measurement and…
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The simple PLC ladder diagram (LD) commands consist of contacts and coils, arranged in sequences that mimic…
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Perhaps the most basic and necessary protective relay function is overcurrent: commanding a circuit breaker 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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In the United States, the most common language used to program PLCs is Ladder Diagram (LD), also known as…
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A fluid is any substance having the ability to flow: to freely change shape and move under the influence of a…
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Electromechanical relays may be connected together to perform logic and control functions, acting as logic…
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An important type of “accessory” relay, especially for legacy electromechanical protective relays,…
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An electric motor is often used as a discrete control element in a control system if driving a pump, conveyor…
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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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Although it seems each model of PLC has its own idiosyncratic standard for programming, there does exist an…
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Virtually any mass above absolute zero temperature emits electromagnetic radiation (photons, or light) as a…
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The concepts of calibration (trimming) and ranging are often difficult for new students of instrumentation to…
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Disturbances in the liquid tend to complicate liquid level measurement. These disturbances may result from…
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Capacitors store energy in electric fields, proportional to the square of voltage. Inductors store energy in…
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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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Weight-based level instruments sense process level in a vessel by directly measuring the weight of the vessel.…
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When I began teaching full-time in 1998, most of what I thought I understood about good teaching was actually…
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For better or worse, there are no fewer than three different forms of PID equations implemented in modern PID…
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Finally, we arrive at the loop diagram (sometimes called a loop sheet) for the compressor surge control system…
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Calculus. Few areas of mathematics are as powerfully useful in describing and analyzing the physical…
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The Law of Continuity for fluids states that the product of mass density (\(\rho\)), cross-sectional pipe area…
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In reliability engineering, it is important to be able to quantity the reliability (or conversely, the…
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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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Since we often use electricity to convey energy from one location to another, it is important to be able to…
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Impedance in a series circuit is the orthogonal sum of resistance and reactance: \[Z = \sqrt{R^2 + (X_L -…
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Two extremely important principles in electric circuits were codified by Gustav Robert Kirchhoff in the year…
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Displacer level instruments exploit Archimedes’ Principle to detect liquid level by continuously…
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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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Some problem-solving techniques are unique to quantitative problems, involving mathematical calculations. In…
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One of the most important accessories for any temperature-sensing element is a pressure-tight sheath known as…
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Tube, like pipe, is a hollow structure designed to provide an enclosed pathway for fluids to flow. In the case…
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