A bridge circuit is basically a pair of voltage dividers where the…
Imagine a major marathon race, where hundreds of runners gather in one…
These fortifications focus on human behavior rather than system design…
A completely different way of measuring liquid level in vessels is to…
I remember first learning about the world-wide Internet, and wondering…
Light has long been used as a long-range signaling medium. While…
An exciting development in industrial instrumentation is the…
In a manually-controlled process, a human operator directly actuates…
At the next OSI Reference Model layer (layer 4) is a set of protocols…
One of the great benefits of digital technology is the ability to…
Many years ago, when I was first learning about electricity, I…
Developed by the Modicon company (the original manufacturer of the…
A design-based fortification is one rooted in technical details of…
The vast majority of PID controllers in service today are digital in…
In the United States, the ANSI and IEEE organizations have…
There are multiple motives for compromising the security of an…
Cyber-security seems to have its own vocabulary, ranging from unwieldy…
Every programmable logic controller must have some means of receiving…
Programmable logic controllers are essentially nothing more than…
An engineer named Bob Metcalfe conceived the idea of Ethernet in 1973,…
To summarize some of the key points and concepts for teaching: Do not…
Sensors used to measure vibration come in three basic types:…
This section does not describe a particular type of flowmeter, but…
A pneumatic controller receives a process variable (PV) signal as a…
Volumes could be written about poor diagnostic technique. The…
AC induction motors are based on the principle of a rotating magnetic…
A flow switch is one detecting the flow of some fluid through a pipe.…
When control valves operate between fully open and fully shut, they…
Although it seems each model of PLC has its own idiosyncratic standard…
A positive displacement flowmeter is a cyclic mechanism built to pass…
A great many chemical composition measurements may be made indirectly…
The efficient identification and correction of instrument calibration…
An electric motor is often used as a discrete control element in a…
For better or worse, there are no fewer than three different forms of…
A laser is a light source emitting waves of light that not only…
Stoichiometry is the accounting of atoms before and after a chemical…
The reason why a pneumatic control valve’s stem position…
Sample sizes of chemical substances are often measured in moles. One…
In this section I will show screenshots from a process loop simulation…
First, let us review some of the properties of differentials and…
Disconnect Switches Disconnects are switches designed to isolate…
Certain types of nuclear radiation easily penetrates the walls of…
Feedback Control System Components Before we begin our discussion on…
The following animation shows a rotating phasor in three-dimensional…
A 4 to 20 mA current signal represents some signal along a 0 to 100…
The concepts of calibration (trimming) and ranging are often difficult…
Atom: the smallest unit of matter that may be isolated by chemical…
An important type of “accessory” relay, especially for…
Constructing PID control systems using discrete components is a…
Like so many other industrial data networks, FOUNDATION Fieldbus is an…
As discussed at the beginning of this chapter, instrumentation safety…
When I began teaching full-time in 1998, most of what I thought I…
Light is known to interact with matter in very specific ways, which…
As a general rule, high achievement only takes place in an atmosphere…
An variable-area flowmeter is one where the fluid must pass through a…
A technological advance introduced in the late 1980’s was HART,…
In contrast to quantitative tuning procedures where definite numerical…
The three “elementary” particles of matter comprising all…
Current is the name we give to the motion of electric charges from a…
Learning PLC programming is a very important skill. If your job…
