An electric motor is often used as a discrete control element in a…
A simple control system drawn in block diagram form looks like this:…
Regulating the electric power sent to an electric motor is a task…
DC electric motors generate torque by a reaction between two magnetic…
Modern DC and AC motor drives provide features useful when using…
The simplest form of 4-20 mA current loop is the type used to…
The key to understanding how three-phase electric motors work is to…
AC induction motors are based on the principle of a rotating magnetic…
There are several different methods useful for causing an AC induction…
The following animation shows how the “rotating” magnetic…
There are several different methods useful for causing an AC induction…
As discussed at the beginning of this chapter, instrumentation safety…
The reason why a pneumatic control valve’s stem position…
In addition to directly performing logic functions, electromechanical…
The simplest form of 4-20 mA current loop is the type used to…
To better understand the design and operation of self-balancing…
Perhaps the most important rule of controller tuning is to know the…
Negative feedback systems, in general, tend to cause confusion for…
In the United States, the most common language used to program PLCs is…
A simple control system drawn in block diagram form looks like this:…
DC electric motors generate torque by a reaction between two magnetic…
AC induction motors are based on the principle of a rotating magnetic…
Process measurements are often of an analog nature: the temperature of…
The simple PLC ladder diagram (LD) commands consist of contacts and…
Non-dispersive analysis, while newer in discovery than dispersive…
A limit switch detects the physical motion of an object by direct…
Virtually any mass above absolute zero temperature emits…
The purpose of a control valve actuator is to provide the motive force…
Modern DC and AC motor drives provide features useful when using…
Perhaps the most basic and necessary protective relay function is…
Suppose we wished to measure the consumption of propane over time for…
Filled-bulb systems exploit the principle of fluid expansion to…
Capacitance Any two electrical conductors separated by an insulating…
Level gauges are perhaps the simplest indicating instrument for liquid…
The vast majority of PID controllers in service today are digital in…
All substances are comprised of various elements in various…
“Radio” systems use electromagnetic fields to communicate…
As we have seen, the concept of differentiation is finding the…
There are many process control applications in the industry where it…
When I began teaching full-time in 1998, most of what I thought I…
Few areas of mathematics are as powerfully useful in describing and…
This section shows some of the many instrument symbols found in…
There are multiple motives for compromising the security of an…
Temperature measurement devices may be classified into two broad…
A flow switch is one detecting the flow of some fluid through a pipe.…
Process analyzers measure the concentration of specific substances for…
A proximity switch is one detecting the proximity (closeness) of some…
At the root of successful system diagnosis is a rigorous adherence to…
Three-phase AC is the dominant mode of electric power generation and…
Impedance in a series circuit is the orthogonal sum of resistance and…
