A simple control system drawn in block diagram form looks like this:…
AC induction motors are based on the principle of a rotating magnetic…
In the United States, the most common language used to program PLCs is…
Process measurements are often of an analog nature: the temperature of…
Modern DC and AC motor drives provide features useful when using…
DC electric motors generate torque by a reaction between two magnetic…
Although it seems each model of PLC has its own idiosyncratic standard…
An electric motor is often used as a discrete control element in a…
Virtually any mass above absolute zero temperature emits…
As discussed at the beginning of this chapter, instrumentation safety…
Phasors are to AC circuit quantities as polarity is to DC circuit…
A bridge circuit is basically a pair of voltage dividers where the…
The reason why a pneumatic control valve’s stem position…
Perhaps the most basic and necessary protective relay function is…
In addition to directly performing logic functions, electromechanical…
The vast majority of PID controllers in service today are digital in…
Imagine a liquid-level control system for a vessel, where the position…
There are several different methods useful for causing an AC induction…
The simple PLC ladder diagram (LD) commands consist of contacts and…
The purpose of a control valve actuator is to provide the motive force…
The Law of Mass Conservation states that matter can neither be created…
As discussed at the beginning of this chapter, instrumentation safety…
Many liquid substances undergo a process whereby their constituent…
Certain types of nuclear radiation easily penetrates the walls of…
“As to methods there may be a million and then some, but…
A fundamental limitation of proportional control has to do with its…
The simplest form of 4-20 mA current loop is the type used to…
The term “grid” refers to the conductors and equipment…
A much simpler alternative to continuous vibration sensors…
The following animation shows how a radio-energy pulse travels down…
One very convenient feature of waves is that their properties are…
Negative feedback systems, in general, tend to cause confusion for…
Process measurements are often of an analog nature: the temperature of…
Suppose we wished to measure the rate of propane gas flow through a…
Self-balancing mechanisms consisting solely of a baffle/nozzle…
An exciting development in industrial instrumentation is the…
DC electric motors generate torque by a reaction between two magnetic…
Abdelaziz, Ahmed (June 2014) Identified numerous typographical errors…
There are many process control applications in the industry where it…
