The reason why a pneumatic control valve’s stem position corresponds linearly to the amount of air…
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An engineer named Bob Metcalfe conceived the idea of Ethernet in 1973, while working for the Xerox research…
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A fundamental principle in instrumentation system troubleshooting is that every instrument has at least one…
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pH is the measurement of the hydrogen ion activity in a liquid solution. It is one of the most common forms of…
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Volumes could be written about poor diagnostic technique. The following mistakes are not intended to comprise…
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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 we have seen, the concept of differentiation is finding the rate-of-change of one variable compared to…
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Feedback Control System Components Before we begin our discussion on process control, we must define a few key…
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Electrical Resistance Resistance (\(R\)) is the dissipative opposition to an electric current, analogous 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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Some analyzers measure the composition of a process stream by directly immersing the sensing element in that…
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The vast majority of modern process transmitters (both analog and digital) come equipped with a feature known…
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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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An important type of “accessory” relay, especially for legacy electromechanical protective relays,…
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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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The electrical conductivity of liquids is an important analytical measurement in many industrial processes.…
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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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As described earlier in this chapter, calibration refers to the adjustment of an instrument so its output…
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Multiple accessories exist for pressure-sensing devices to function optimally in challenging process…
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Programmable logic controllers are essentially nothing more than special-purpose, industrial computers. As…
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Capacitive level instruments measure electrical capacitance of a conductive rod inserted vertically into a…
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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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A fundamental principle in instrumentation system troubleshooting is that every instrument has at least one…
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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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Stoichiometry is the accounting of atoms before and after a chemical reaction. It is an expression of the Law…
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“Polyphase” means “many phases,” describing a form of AC electrical system where…
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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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Electrical power grids primarily consist of three-phase AC circuits. This means most power lines (transmission…
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The digital multimeter (DMM) is quite possibly the most useful tool in the instrument technician’s…
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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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Regardless of valve type, all stem-actuated control valves require some form of seal allowing motion of the…
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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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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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A whole class of problem-solving techniques focuses on altering the given problem into a simpler form that is…
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Disturbances in the liquid tend to complicate liquid level measurement. These disturbances may result from…
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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 machine in the broad sense of the word is any device designed to translate some form of energy into useful…
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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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Some of the simplest types of digital communication networks found in industry are defined by the EIA…
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Most of these formulae appear in molecular chemical form rather than structural form. For example, ethanol…
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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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A very common form of on/off valve used for pneumatic and hydraulic systems alike is the solenoid valve. A…
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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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A technological advance introduced in the late 1980’s was HART, an acronym standing for Highway…
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(Will be addressed in future versions of this book)
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DC electric current signals may also be used to communicate process measurement information from transmitters…
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“Polyphase” means “many phases,” describing a form of AC electrical system where…
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Mechanical pressure-sensing elements include the bellows, the diaphragm, and the bourdon tube. Each of these…
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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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A laser is a light source emitting waves of light that not only share the exact same frequency (color)…
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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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An on/off valve is the fluid equivalent of an electrical switch: a device that either allows unimpeded flow or…
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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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Using filter cells to eliminate wavelengths associated with interfering gases is called positive filtering in…
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The very purpose of physics is to quantitatively describe and explain the physical world in as few terms as…
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Stoichiometry is the accounting of atoms before and after a chemical reaction. It is an expression of the Law…
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Cyber-security seems to have its own vocabulary, ranging from unwieldy technical acronyms to slang terms…
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As described earlier in this chapter, calibration refers to the adjustment of an instrument so its output…
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Electrical Resistance Resistance (\(R\)) is the dissipative opposition to an electric current, analogous to…
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Nearly every technical course teaches and tests students on definitions, basic concepts, and at least some…
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