In the United States, the most common language used to program PLCs is Ladder Diagram (LD), also known as…
Textbook
To review, voltage is the measure of potential energy available to electric charges. Current is the uniform…
Textbook
Perhaps the most basic and necessary protective relay function is overcurrent: commanding a circuit breaker to…
Textbook
Textbook
Few areas of mathematics are as powerfully useful in describing and analyzing the physical world as calculus:…
Textbook
The term “grid” refers to the conductors and equipment interconnecting power sources to power…
Textbook
The following animation shows how the “rotating” magnetic field of a three-phase AC induction…
Textbook
Fieldbus devices require far more attention in their initial setup and commissioning than their analog…
Textbook
An variable-area flowmeter is one where the fluid must pass through a restriction whose area increases with…
Textbook
A proximity switch is one detecting the proximity (closeness) of some object. By definition, these switches…
Textbook
Imagine a liquid-level control system for a vessel, where the position of a level-sensing float directly sets…
Textbook
A sliding-stem valve body is one where the moving parts slide with a linear motion. Some examples of…
Textbook
One of the fundamental laws of electric circuits is Kirchhoff’s Current Law, which states the algebraic…
Textbook
Process analyzers measure the concentration of specific substances for the purpose of measuring and/or…
Textbook
A hand switch is exactly what the name implies: an electrical switch actuated by a person’s hand motion.…
Textbook
DC electric motors generate torque by a reaction between two magnetic fields: one field established by…
Textbook
A variety of problem-solving techniques have been presented for students over the years which are all helpful…
Textbook
There are many process control applications in the industry where it is desirable to have multiple control…
Textbook
The vast majority of modern process transmitters (both analog and digital) come equipped with a feature known…
Textbook
A number of different sensors used in instrumentation generate DC voltage signals proportional to the process…
Textbook
The following animation shows the calculus concepts of differentiation and integration (with respect to time)…
Textbook
Displacer level instruments exploit Archimedes’ Principle to detect liquid level by continuously…
Textbook
Process analyzers measure the concentration of specific substances for the purpose of measuring and/or…
Textbook
There are several different methods useful for causing an AC induction motor to brake, or slow down: DC…
Textbook
To understand just how different FOUNDATION Fieldbus is from other digital instrument systems, consider a…
Textbook
Binary patterns are not just able to represent numerical values. Given a standardized code, they may represent…
Textbook
As a general rule, high achievement only takes place in an atmosphere of high expectations. Sometimes these…
Textbook
A whole class of problem-solving techniques focuses on altering the given problem into a simpler form that is…
Textbook
Sensors used to measure vibration come in three basic types: displacement, velocity, and acceleration.…
Textbook
Stoichiometry is the accounting of atoms before and after a chemical reaction. It is an expression of the Law…
Textbook
Sometimes we encounter a diversity of instrument signal standards in one control system. Such is the case with…
Textbook
While the term “probability” may evoke images of imprecision, probability is in fact an exact…
Textbook
A very common method for directly controlling low flow rates of fluids is to use a device known as a metering…
Textbook
As we have seen, the concept of integration is finding the accumulation of one variable multiplied by another…
Textbook
A temperature switch is one detecting the temperature of some substance. Temperature switches often use…
Textbook
The dispersion of visible light into its constituent colors goes all the way back to the 17th century with…
Textbook
A pneumatic controller receives a process variable (PV) signal as a variable air pressure, compares that…
Textbook
Sample sizes of chemical substances are often measured in moles. One mole of a substance is defined as a…
Textbook
The two “process variables” we rely on most heavily in the field of electrical measurement and…
Textbook
Earlier in this chapter you were shown a model of a nitrogen atom with a dense nucleus (comprised of protons…
Textbook