Negative feedback systems, in general, tend to cause confusion for…
Virtually any mass above absolute zero temperature emits…
Modern DC and AC motor drives provide features useful when using…
In order for any PID controller to be practical, it must be able to do…
In addition to directly performing logic functions, electromechanical…
Imagine a liquid-level control system for a vessel, where the position…
As discussed at the beginning of this chapter, instrumentation safety…
There are several different methods useful for causing an AC induction…
To better understand the design and operation of self-balancing…
Perhaps the most important rule of controller tuning is to know the…
The purpose of a control valve actuator is to provide the motive force…
A bridge circuit is basically a pair of voltage dividers where the…
AC induction motors are based on the principle of a rotating magnetic…
Phasors are to AC circuit quantities as polarity is to DC circuit…
The reason why a pneumatic control valve’s stem position…
Perhaps the most basic and necessary protective relay function is…
Feedback Control System Components Before we begin our discussion on…
The vast majority of PID controllers in service today are digital in…
Process measurements are often of an analog nature: the temperature of…
The simplest form of 4-20 mA current loop is the type used to…
Modern analog-to-digital converters are phenomenally accurate,…
To better understand the design and operation of self-balancing…
A fluid is any substance having the ability to flow: to freely change…
A Safety Instrumented Function, or SIF, is one or more components…
Light is known to interact with matter in very specific ways, which…
Many traditional flowmeter technologies respond to the volumetric flow…
The following animation shows how the “rotating” magnetic…
(Will be addressed in future versions of this book)
Cyber-security seems to have its own vocabulary, ranging from unwieldy…
DC electric current signals may also be used to communicate process…
Process analyzers measure the concentration of specific substances for…
A temperature switch is one detecting the temperature of some…
While 50 and 51 (instantaneous and time overcurrent) relay functions…
The advent of “smart” field instruments containing…
Fieldbus devices require far more attention in their initial setup and…
Filled-bulb systems exploit the principle of fluid expansion to…
A laser is a light source emitting waves of light that not only…
Level gauges are perhaps the simplest indicating instrument for liquid…
Area refers to the size of two-dimensional surface. Volume refers to…
All substances are comprised of various elements in various…
