A simple control system drawn in block diagram form looks like this: Information from the measuring device…
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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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Abdelaziz, Ahmed (June 2014) Identified numerous typographical errors throughout the book, mostly repeated…
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When a high-energy photon strikes an atom, it may eject one of the lower-level electrons from its shell,…
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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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Valve actuators provide force to move control valve trim. For precise positioning of a control valve, there…
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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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The following collection of photographs chronicles the complete disassembly of a Fisher E-body globe valve…
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A different strategy for controlling the flow of fluid is to insert a rotary element into the flow path.…
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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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Most pneumatic instruments use a simple but highly sensitive mechanism for converting mechanical motion into…
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Displacer level instruments exploit Archimedes’ Principle to detect liquid level by continuously…
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Multiple accessories exist for pressure-sensing devices to function optimally in challenging process…
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One of the most common, and most useful, pressure measuring instruments in industry is the differential…
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As discussed at the beginning of this chapter, instrumentation safety may be broadly divided into two…
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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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Sometimes we encounter a diversity of instrument signal standards in one control system. Such is the case with…
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Given the ability of pressurized fluids to transmit force over long distances, it is not surprising that many…
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Control valves are supposed to deliver reliable, repeatable control of process fluid flow rate over a wide…
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Another category of control strategies involves the use of signal relays or function blocks with the ability…
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Flow, by definition, is the passage of material from one location to another over time. So far this chapter…
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The following animation shows the calculus concepts of differentiation and integration (with respect to time)…
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DC electric motors generate torque by a reaction between two magnetic fields: one field established by…
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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 summarize some of the key points and concepts for teaching: Do not waste class time transmitting facts to…
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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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A limitation inherent to pneumatic valve actuators is the amount of air flow required to or from the actuator…
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(Will be addressed in future versions of this book)
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In addition to Ohm’s Law, we have a set of rules describing how voltages, currents, and resistances…
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Human-machine interfaces, or HMIs, are a critical part of nearly all control systems, complementing the…
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One of the simplest classes of temperature sensor is one where temperature effects a change in electrical…
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Once while working as an instrument technician in an aluminum foundry, a mechanic asked me what it was that I…
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Imagine a liquid-level control system for a vessel, where the position of a level-sensing float directly sets…
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Converting between disparate units of measurement is the bane of many science students. The problem is worse…
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A much simpler alternative to continuous vibration sensors (displacement or acceleration) and monitoring…
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So far we have just looked at instruments that sense, control, and influence process variables. Transmitters,…
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Modern DC and AC motor drives provide features useful when using electric motors as final control elements.…
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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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Earlier in this chapter you were shown a model of a nitrogen atom with a dense nucleus (comprised of protons…
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A temperature switch is one detecting the temperature of some substance. Temperature switches often use…
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Virtually any mass above absolute zero temperature emits electromagnetic radiation (photons, or light) as a…
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These fortifications focus on human behavior rather than system design or component selection. In some ways…
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As discussed at the beginning of this chapter, instrumentation safety may be broadly divided into two…
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When a high-energy photon strikes an atom, it may eject one of the lower-level electrons from its shell,…
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Instrument technicians should not have to concern themselves over the programming details internal to digital…
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To understand just how different FOUNDATION Fieldbus is from other digital instrument systems, consider a…
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Level gauges are perhaps the simplest indicating instrument for liquid level in a vessel. They are often found…
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Another category of control strategies involves the use of signal relays or function blocks with the ability…
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Light has long been used as a long-range signaling medium. While communication by light through open air is…
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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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Although analog electronic process controllers are considered a newer technology than pneumatic process…
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Like many other mathematical operations, the derivative and the integral perform inverse operations from each…
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A level switch is one detecting the level of liquid or solid (granules or powder) in a vessel. Level switches…
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Sensors used to measure vibration come in three basic types: displacement, velocity, and acceleration.…
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(Will be addressed in future versions of this book)
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A design-based fortification is one rooted in technical details of system architecture and functionality. Some…
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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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One of the great benefits of digital technology is the ability to communicate vast amounts of information over…
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Fluid pressure exerts force on any surface area it contacts, as described by the formula \(F = PA\). One…
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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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