Process measurements are often of an analog nature: the temperature of a furnace, the rate of fluid flow…
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The disadvantages of pneumatic instruments are painfully evident to anyone familiar with both pneumatic and…
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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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Three-phase AC is the dominant mode of electric power generation and distribution in modern societies.…
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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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The following animation shows a rotating phasor in three-dimensional form. The phasor rotates in a complex…
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Regulating the electric power sent to an electric motor is a task performed by high-speed switching…
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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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There is much to be said for neatness of assembly in electrical signal wiring. Even though the electrons…
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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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A fundamental principle in instrumentation system troubleshooting is that every instrument has at least one…
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This animation shows the basic operation of a gas chromatograph, showing the separation of different molecular…
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A technological advance introduced in the late 1980’s was HART, an acronym standing for Highway…
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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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DC electric current signals may also be used to communicate process measurement information from transmitters…
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In addition to directly performing logic functions, electromechanical relays may also be used as interposing…
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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 Safety Instrumented Function, or SIF, is one or more components designed to execute a specific…
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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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Once while working as an instrument technician in an aluminum foundry, a mechanic asked me what it was that I…
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Feedback obtained from industrial users of FF reveal a common pattern: Fieldbus is a powerful and reliable…
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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 some process applications, it is important that the control valve be able to completely stop fluid flow…
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Self-balancing mechanisms consisting solely of a baffle/nozzle detector coupled to a feedback bellows, while…
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When I began teaching full-time in 1998, most of what I thought I understood about good teaching was actually…
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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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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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Finally, we arrive at the loop diagram (sometimes called a loop sheet) for the compressor surge control system…
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A much simpler alternative to continuous vibration sensors (displacement or acceleration) and monitoring…
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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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The efficient identification and correction of instrument calibration errors is an important function for…
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In reliability engineering, it is important to be able to quantity the reliability (or conversely, 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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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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The advent of “smart” field instruments containing microprocessors has been a great advance for…
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Any power grid large enough to meet the demand of an entire nation must have multiple generators drawing from…
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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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Although analog electronic process controllers are considered a newer technology than pneumatic process…
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The three “elementary” particles of matter comprising all atoms are electrons, protons, and…
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The purpose of a control valve actuator is to provide the motive force to operate a valve mechanism. Both…
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