The two “process variables” we rely on most heavily in the field of electrical measurement and…
Textbook
“Polyphase” means “many phases,” describing a form of AC electrical system where…
Textbook
Those familiar with industrial instrumentation will find much within the electric power industry remarkably…
Textbook
An important type of “accessory” relay, especially for legacy electromechanical protective relays,…
Textbook
Modern analog-to-digital converters are phenomenally accurate, dependable, repeatable, and surprisingly…
Textbook
Perhaps the most basic and necessary protective relay function is overcurrent: commanding a circuit breaker to…
Textbook
A fluid is any substance having the ability to flow: to freely change shape and move under the influence of a…
Textbook
There are several different methods useful for causing an AC induction motor to brake, or slow down: DC…
Textbook
Regulating the electric power sent to an electric motor is a task performed by high-speed switching…
Textbook
Human-machine interfaces, or HMIs, are a critical part of nearly all control systems, complementing the…
Textbook
One of the fundamental laws of electric circuits is Kirchhoff’s Current Law, which states the algebraic…
Textbook
In addition to directly performing logic functions, electromechanical relays may also be used as interposing…
Textbook
For better or worse, there are no fewer than three different forms of PID equations implemented in modern PID…
Textbook
A hand switch is exactly what the name implies: an electrical switch actuated by a person’s hand motion.…
Textbook
A flow switch is one detecting the flow of some fluid through a pipe. Flow switches often use…
Textbook
Perhaps the simplest form of solid or liquid level measurement is with a float: a device that rides on the…
Textbook
Shown here is a partial listing of principles applied in the subject matter of this chapter, given for the…
Textbook
Fluid pressure exerts force on any surface area it contacts, as described by the formula \(F = PA\). One…
Textbook
A machine in the broad sense of the word is any device designed to translate some form of energy into useful…
Textbook
To show a practical process example, let’s examine three diagrams for a compressor control system,…
Textbook
Some problem-solving techniques are unique to quantitative problems, involving mathematical calculations. In…
Textbook
A very common method for directly controlling low flow rates of fluids is to use a device known as a metering…
Textbook
Electromechanical relays may be connected together to perform logic and control functions, acting as logic…
Textbook
Disconnect Switches Disconnects are switches designed to isolate sections of a power system in case of damage…
Textbook
Every programmable logic controller must have some means of receiving and interpreting signals from real-world…
Textbook
A chemical reaction resulting in a net release of energy is called exothermic. Conversely, a chemical reaction…
Textbook
There is much to be said for neatness of assembly in electrical signal wiring. Even though the electrons…
Textbook
The simplest form of 4-20 mA current loop is the type used to represent the output of a process controller,…
Textbook
It is often useful to express the amplitude of an alternating quantity such as voltage or current in terms…
Textbook
Capacitance Any two electrical conductors separated by an insulating medium possess the characteristic called…
Textbook
A limit switch detects the physical motion of an object by direct contact with that object. An example of a…
Textbook
Those familiar with industrial instrumentation will find much within the electric power industry remarkably…
Textbook
Developed by the Modicon company (the original manufacturer of the Programmable Logic Controller, or PLC) in…
Textbook
These fortifications focus on human behavior rather than system design or component selection. In some ways…
Textbook
Constructing PID control systems using discrete components is a fairly simple method involving operational…
Textbook
pH is the measurement of the hydrogen ion activity in a liquid solution. It is one of the most common forms of…
Textbook
Hydrogen ion activity in aqueous (water-solvent) solutions is a very important parameter for a wide variety of…
Textbook
The simple PLC ladder diagram (LD) commands consist of contacts and coils, arranged in sequences that mimic…
Textbook
A level switch is one detecting the level of liquid or solid (granules or powder) in a vessel. Level switches…
Textbook
The Law of Continuity for fluids states that the product of mass density (\(\rho\)), cross-sectional pipe area…
Textbook
All masses require force to accelerate (we can also think of this in terms of the mass generating a reaction…
Textbook
The vast majority of modern process transmitters (both analog and digital) come equipped with a feature known…
Textbook
The following photograph shows a large air blower in a wastewater treatment facility equipped with a…
Textbook
Data-processing modules within FF systems are known as function blocks. Sometimes these blocks serve merely to…
Textbook
Perhaps the most basic and necessary protective relay function is overcurrent: commanding a circuit breaker to…
Textbook
The reason why a pneumatic control valve’s stem position corresponds linearly to the amount of air…
Textbook
The term “grid” refers to the conductors and equipment interconnecting power sources to power…
Textbook
To review, voltage is the measure of potential energy available to electric charges. Current is the uniform…
Textbook
Virtually any mass above absolute zero temperature emits electromagnetic radiation (photons, or light) as a…
Textbook
Tube, like pipe, is a hollow structure designed to provide an enclosed pathway for fluids to flow. In the case…
Textbook
Most pneumatic instruments use a simple but highly sensitive mechanism for converting mechanical motion into…
Textbook
Up until this point, we have explored various types of instrumentation diagram, each one making reference to…
Textbook
Facebook
Google
GitHub
Linkedin