Sometimes we encounter a diversity of instrument signal standards in one control system. Such is the case with…
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A great many precision instruments use the principle of balance to measure some quantity. Perhaps the simplest…
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The disadvantages of pneumatic instruments are painfully evident to anyone familiar with both pneumatic and…
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Self-balancing pneumatic instrument mechanisms are very similar to negative-feedback operational amplifier…
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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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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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To better understand the design and operation of self-balancing pneumatic mechanisms, it is helpful to examine…
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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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So far we have just looked at instruments that sense, control, and influence process variables. Transmitters,…
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Up until this point, we have explored various types of instrumentation diagram, each one making reference to…
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One of the most common, and most useful, pressure measuring instruments in industry is the differential…
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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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All masses require force to accelerate (we can also think of this in terms of the mass generating a reaction…
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In some process applications, it is important that the control valve be able to completely stop fluid flow…
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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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Tube, like pipe, is a hollow structure designed to provide an enclosed pathway for fluids to flow. In the case…
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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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As discussed at the beginning of this chapter, instrumentation safety may be broadly divided into two…
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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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There are many process control applications in the industry where it is desirable to have multiple control…
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(Will be addressed in future versions of this book)
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As discussed at the beginning of this chapter, instrumentation safety may be broadly divided into two…
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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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In contrast to quantitative tuning procedures where definite numerical values for P, I, and D controller…
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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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A powerful mathematical concept useful for analyzing practically any physical system – 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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For better or worse, there are no fewer than three different forms of PID equations implemented in modern PID…
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While the term “probability” may evoke images of imprecision, probability is in fact an exact…
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Area refers to the size of two-dimensional surface. Volume refers to the size of a three-dimensional space. To…
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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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Cyber-security seems to have its own vocabulary, ranging from unwieldy technical acronyms to slang terms…
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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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A very simple device used to measure pressure is the manometer: a fluid-filled tube where an applied gas…
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The term “grid” refers to the conductors and equipment interconnecting power sources to power…
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Constructing PID control systems using discrete components is a fairly simple method involving operational…
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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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The final element of PID control is the “D” term, which stands for derivative. This is a calculus…
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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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