In the United States, the ANSI and IEEE organizations have standardized a set of numerical codes referring to…
Textbook
Circuit breakers used in residential, commercial, and light industrial service are self-tripping devices: they…
Textbook
Electrical power grids primarily consist of three-phase AC circuits. This means most power lines (transmission…
Textbook
Disconnect Switches Disconnects are switches designed to isolate sections of a power system in case of damage…
Textbook
The transformer is one of the most important components in all of AC circuitry. Principally used to…
Textbook
Current is the name we give to the motion of electric charges from a point of high potential to a point of low…
Textbook
By definition, a source is a device delivering energy into a system, while a load is a device extracting…
Textbook
Those familiar with industrial instrumentation will find much within the electric power industry remarkably…
Textbook
While 50 and 51 (instantaneous and time overcurrent) relay functions monitor line current magnitude and guard…
Textbook
The two “process variables” we rely on most heavily in the field of electrical measurement and…
Textbook
The term “grid” refers to the conductors and equipment interconnecting power sources to power…
Textbook
A form of protection against faults on long-distance power lines is called distance relaying, so named because…
Textbook
“Polyphase” means “many phases,” describing a form of AC electrical system where…
Textbook
Three-phase AC is the dominant mode of electric power generation and distribution in modern societies.…
Textbook
One of the fundamental laws of electric circuits is Kirchhoff’s Current Law, which states the algebraic…
Textbook
Since we often use electricity to convey energy from one location to another, it is important to be able to…
Textbook
The final element of PID control is the “D” term, which stands for derivative. This is a calculus…
Textbook
A great many precision instruments use the principle of balance to measure some quantity. Perhaps the simplest…
Textbook
The concepts of calibration (trimming) and ranging are often difficult for new students of instrumentation to…
Textbook
“Feedforward” is a rather under-used control strategy capable of managing a great many types of…
Textbook
When a high-energy photon strikes an atom, it may eject one of the lower-level electrons from its shell,…
Textbook
A chemical reaction resulting in a net release of energy is called exothermic. Conversely, a chemical reaction…
Textbook
Human-machine interfaces, or HMIs, are a critical part of nearly all control systems, complementing the…
Textbook
Perhaps the most important rule to obey when using pneumatic instruments is to maintain clean and dry…
Textbook
Developed by the Modicon company (the original manufacturer of the Programmable Logic Controller, or PLC) in…
Textbook
What is Calibration? To calibrate an instrument means to check and adjust (if necessary) its response so the…
Textbook
When I began teaching full-time in 1998, most of what I thought I understood about good teaching was actually…
Textbook
In a manually-controlled process, a human operator directly actuates some form of final control element…
Textbook
The electrical conductivity of liquids is an important analytical measurement in many industrial processes.…
Textbook
Mechanical pressure-sensing elements include the bellows, the diaphragm, and the bourdon tube. Each of these…
Textbook
To summarize some of the key points and concepts for teaching: Do not waste class time transmitting facts to…
Textbook
One of the most important accessories for any temperature-sensing element is a pressure-tight sheath known as…
Textbook
The purpose of a control valve actuator is to provide the motive force to operate a valve mechanism. Both…
Textbook
Control valves are supposed to deliver reliable, repeatable control of process fluid flow rate over a wide…
Textbook
As previously defined, calibration refers to the checking and adjustment of an instrument so that its output…
Textbook
All substances are comprised of various elements in various combinations and proportions. Elements may thus be…
Textbook
Control valves are supposed to deliver reliable, repeatable control of process fluid flow rate over a wide…
Textbook
The purpose of a control valve actuator is to provide the motive force to operate a valve mechanism. Both…
Textbook
Electrical power grids primarily consist of three-phase AC circuits. This means most power lines (transmission…
Textbook
A great many chemical composition measurements may be made indirectly by means of electricity, if those…
Textbook
Capacitance Any two electrical conductors separated by an insulating medium possess the characteristic called…
Textbook
Process measurements are often of an analog nature: the temperature of a furnace, the rate of fluid flow…
Textbook
There are multiple motives for compromising the security of an industrial control system, some of which…
Textbook
Thermodynamics is the study of heat, temperature, and their related effects in physical systems. As a subject,…
Textbook
In some process applications, it is important that the control valve be able to completely stop fluid flow…
Textbook
Textbook
In addition to directly performing logic functions, electromechanical relays may also be used as interposing…
Textbook
Imagine a liquid-level control system for a vessel, where the position of a level-sensing float sets the…
Textbook
Regardless of valve type, all stem-actuated control valves require some form of seal allowing motion of the…
Textbook
Every programmable logic controller must have some means of receiving and interpreting signals from real-world…
Textbook
To show a practical process example, let’s examine three diagrams for a compressor control system,…
Textbook
As a general rule, high achievement only takes place in an atmosphere of high expectations. Sometimes these…
Textbook
The following photograph shows a large air blower in a wastewater treatment facility equipped with a…
Textbook
A damper (otherwise known as a louvre) is a multi-element flow control device generally used to throttle large…
Textbook
Take for instance the problem of measuring fluid flow through a pipe. To the layperson, this may seem to be a…
Textbook
A great many precision instruments use the principle of balance to measure some quantity. Perhaps the simplest…
Textbook
Facebook
Google
GitHub
Linkedin