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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“Polyphase” means “many phases,” describing a form of AC electrical system where…
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Filled-bulb systems exploit the principle of fluid expansion to measure temperature. If a fluid is enclosed in…
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Instrument technicians should not have to concern themselves over the programming details internal to digital…
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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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A technological advance introduced in the late 1980’s was HART, an acronym standing for Highway…
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Data-processing modules within FF systems are known as function blocks. Sometimes these blocks serve merely to…
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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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Learning is not merely a process of information transfer. It is first and foremost a transformation of…
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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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Measuring the flow rate of liquid through an open channel is not unlike measuring the flow rate of a liquid…
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Much of our knowledge about atomic structure comes from experimental data relating the interaction between…
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Self-balancing mechanisms consisting solely of a baffle/nozzle detector coupled to a feedback bellows, while…
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Take for instance the problem of measuring fluid flow through a pipe. To the layperson, this may seem to be a…
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“Feedforward” is a rather under-used control strategy capable of managing a great many types of…
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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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A unique form of differential pressure-based flow measurement deserves its own section in this flow…
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As we have seen, the concept of integration is finding the accumulation of one variable multiplied by another…
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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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Fieldbus devices require far more attention in their initial setup and commissioning than their analog…
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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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A bridge circuit is basically a pair of voltage dividers where the circuit output is taken as the difference…
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When control valves operate between fully open and fully shut, they serve much the same purpose in process…
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Filled-bulb systems exploit the principle of fluid expansion to measure temperature. If a fluid is enclosed in…
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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 reason why a pneumatic control valve’s stem position corresponds linearly to the amount of air…
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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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A laser is a light source emitting waves of light that not only share the exact same frequency (color)…
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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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The efficient identification and correction of instrument calibration errors is an important function for…
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In the United States, the ANSI and IEEE organizations have standardized a set of numerical codes referring to…
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Non-dispersive analysis, while newer in discovery than dispersive analysis (Isaac Newton’s 17th-century…
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Light is known to interact with matter in very specific ways, which may be exploited as a means of measuring…
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An important type of “accessory” relay, especially for legacy electromechanical protective relays,…
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Control strategies such as cascade, ratio, feedforward, and those containing limit and selector functions can…
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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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Any physical location in an industrial facility harboring the potential of explosion due to the presence of…
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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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Disturbances in the liquid tend to complicate liquid level measurement. These disturbances may result from…
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Imagine a major marathon race, where hundreds of runners gather in one place to compete. When the starting gun…
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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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Valve actuators provide force to move control valve trim. For precise positioning of a control valve, there…
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A unique form of differential pressure-based flow measurement deserves its own section in this flow…
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Perhaps the most valuable skill an instrument technician can possess is the ability to efficiently diagnose…
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“Feedforward” is a rather under-used control strategy capable of managing a great many types of…
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A special type flowmeter suited for powdered or granular solids is the weighfeeder. One of the most common…
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Fieldbus devices require far more attention in their initial setup and commissioning than their analog…
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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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A limitation inherent to pneumatic valve actuators is the amount of air flow required to or from the actuator…
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Imagine a liquid-level control system for a vessel, where the position of a level-sensing float sets the…
Textbook
The simple PLC ladder diagram (LD) commands consist of contacts and coils, arranged in sequences that mimic…
Textbook
A flow switch is one detecting the flow of some fluid through a pipe. Flow switches often use…
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Every programmable logic controller must have some means of receiving and interpreting signals from real-world…
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Self-balancing mechanisms consisting solely of a baffle/nozzle detector coupled to a feedback bellows, while…
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“Radio” systems use electromagnetic fields to communicate information over long distances through…
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Learning is not merely a process of information transfer. It is first and foremost a transformation of…
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At the next OSI Reference Model layer (layer 4) is a set of protocols specifying how reliable communication…
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Most of these formulae appear in molecular chemical form rather than structural form. For example, ethanol…
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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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A great many chemical composition measurements may be made indirectly by means of electricity, if those…
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