A simple control system drawn in block diagram form looks like this: Information from the measuring device…
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The key to understanding how three-phase electric motors work is to have an accurate mental picture of the…
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The following animation shows how the “rotating” magnetic field of a three-phase AC induction…
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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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An electric motor is often used as a discrete control element in a control system if driving a pump, conveyor…
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AC induction motors are based on the principle of a rotating magnetic field produced by a set of stationary…
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The simplest form of 4-20 mA current loop is the type used to represent the output of a process controller,…
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DC electric motors generate torque by a reaction between two magnetic fields: one field established by…
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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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Modern DC and AC motor drives provide features useful when using electric motors as final control elements.…
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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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Negative feedback systems, in general, tend to cause confusion for those first learning their fundamental…
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Virtually any mass above absolute zero temperature emits electromagnetic radiation (photons, or light) as a…
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The vast majority of PID controllers in service today are digital in nature. Microprocessors executing PID…
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A simple control system drawn in block diagram form looks like this: Information from the measuring device…
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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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Although it seems each model of PLC has its own idiosyncratic standard for programming, there does exist an…
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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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In addition to directly performing logic functions, electromechanical relays may also be used as interposing…
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There are several different methods useful for causing an AC induction motor to brake, or slow down: DC…
Textbook
Perhaps the most basic and necessary protective relay function is overcurrent: commanding a circuit breaker to…
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An electric motor is often used as a discrete control element in a control system if driving a pump, conveyor…
Textbook
AC induction motors are based on the principle of a rotating magnetic field produced by a set of stationary…
Textbook
The simplest form of 4-20 mA current loop is the type used to represent the output of a process controller,…
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Process measurements are often of an analog nature: the temperature of a furnace, the rate of fluid flow…
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Perhaps the most important rule of controller tuning is to know the process before attempting to adjust the…
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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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A bridge circuit is basically a pair of voltage dividers where the circuit output is taken as the difference…
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As discussed at the beginning of this chapter, instrumentation safety may be broadly divided into two…
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Non-dispersive analysis, while newer in discovery than dispersive analysis (Isaac Newton’s 17th-century…
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An electric motor is often used as a discrete control element in a control system if driving a pump, conveyor…
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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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Level gauges are perhaps the simplest indicating instrument for liquid level in a vessel. They are often found…
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Process analyzers measure the concentration of specific substances for the purpose of measuring and/or…
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A variety of problem-solving techniques have been presented for students over the years which are all helpful…
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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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Using filter cells to eliminate wavelengths associated with interfering gases is called positive filtering in…
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A chemical reaction resulting in a net release of energy is called exothermic. Conversely, a chemical reaction…
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Electromechanical relays may be connected together to perform logic and control functions, acting as logic…
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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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AC induction motors are based on the principle of a rotating magnetic field produced by a set of stationary…
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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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In November of 2007 a new computer virus was submitted to a virus scanning service. The purpose of this new…
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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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Calculus. Few areas of mathematics are as powerfully useful in describing and analyzing the physical…
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To understand just how different FOUNDATION Fieldbus is from other digital instrument systems, consider a…
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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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Every flow-measuring instrument exploits a physical principle to measure the flow rate of fluid stream.…
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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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A unique form of differential pressure-based flow measurement deserves its own section in this flow…
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