Learning PLC programming is a very important skill. If your job involves programming, then you will likely…
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So far we have just looked at instruments that sense, control, and influence process variables. Transmitters,…
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The vast majority of PID controllers in service today are digital in nature. Microprocessors executing PID…
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Every programmable logic controller must have some means of receiving and interpreting signals from real-world…
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The following photograph shows a large air blower in a wastewater treatment facility equipped with a…
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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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Labwork is an essential part of any science-based curriculum. Here, much improvement may be made over the…
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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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Steam boilers are very common in industry, principally because steam power is so useful. Common uses for steam…
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While the term “probability” may evoke images of imprecision, probability is in fact an exact…
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There are multiple motives for compromising the security of an industrial control system, some of which…
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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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Programmable logic controllers are essentially nothing more than special-purpose, industrial computers. As…
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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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Atom: the smallest unit of matter that may be isolated by chemical means. Particle: a part of an atom,…
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Capacitive level instruments measure electrical capacitance of a conductive rod inserted vertically into a…
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Much of our knowledge about atomic structure comes from experimental data relating the interaction between…
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A fundamental limitation of proportional control has to do with its response to changes in setpoint and…
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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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The electrical conductivity of liquids is an important analytical measurement in many industrial processes.…
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“Polyphase” means “many phases,” describing a form of AC electrical system where…
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Control strategies such as cascade, ratio, feedforward, and those containing limit and selector functions can…
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A whole class of problem-solving techniques focuses on altering the given problem into a simpler form that is…
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Earlier in this chapter you were shown a model of a nitrogen atom with a dense nucleus (comprised of protons…
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(Will be addressed in future versions of this book)
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Several different technologies exist for the conversion of fluid pressure into an electrical signal response.…
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Programmable logic controllers are essentially nothing more than special-purpose, industrial computers. As…
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Calculus. Few areas of mathematics are as powerfully useful in describing and analyzing the physical…
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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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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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Mechanical pressure-sensing elements include the bellows, the diaphragm, and the bourdon tube. Each of these…
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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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An important legacy technology for all kinds of continuous measurement is the self-balancing system. A…
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A bridge circuit is basically a pair of voltage dividers where the circuit output is taken as the difference…
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The Law of Mass Conservation states that matter can neither be created nor destroyed. The Law of Energy…
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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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PID control can be a confusing concept to understand. Here, a brief summary of each term within PID (P. I, and…
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A limit switch detects the physical motion of an object by direct contact with that object. An example of a…
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Thermodynamics is the study of heat, temperature, and their related effects in physical systems. As a subject,…
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The transformer is one of the most important components in all of AC circuitry. Principally used to…
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As previously defined, calibration refers to the checking and adjustment of an instrument so that its output…
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The vast majority of PID controllers in service today are digital in nature. Microprocessors executing PID…
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A Safety Instrumented Function, or SIF, is one or more components designed to execute a specific…
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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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The Law of Continuity for fluids states that the product of mass density (\(\rho\)), cross-sectional pipe area…
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An variable-area flowmeter is one where the fluid must pass through a restriction whose area increases with…
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Displacer level instruments exploit Archimedes’ Principle to detect liquid level by continuously…
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A unique form of differential pressure-based flow measurement deserves its own section in this flow…
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Several different technologies exist for the conversion of fluid pressure into an electrical signal response.…
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As a general rule, high achievement only takes place in an atmosphere of high expectations. Sometimes these…
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The following animation shows a rotating phasor in three-dimensional form. The phasor rotates in a complex…
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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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The final element of PID control is the “D” term, which stands for derivative. This is a calculus…
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Valve actuators provide force to move control valve trim. For precise positioning of a control valve, there…
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