Some of the simplest types of digital communication networks found in…
Programmable logic controllers are essentially nothing more than…
Light has long been used as a long-range signaling medium. While…
The vast majority of PID controllers in service today are digital in…
Developed by the Modicon company (the original manufacturer of the…
I remember first learning about the world-wide Internet, and wondering…
Labwork is an essential part of any science-based curriculum. Here,…
It is possible to convey electrical power and communicate analog…
A design-based fortification is one rooted in technical details of…
DC electric current signals may also be used to communicate process…
Layer 1 of the OSI Reference Model is where we define the…
RTDs are completely passive sensing elements, requiring the…
Some self-powered (4-wire) analog electronic transmitters are designed…
One of the great benefits of digital technology is the ability to…
There is much to be said for neatness of assembly in electrical signal…
An engineer named Bob Metcalfe conceived the idea of Ethernet in 1973,…
pH is the measurement of the hydrogen ion activity in a liquid…
Learning PLC programming is a very important skill. If your job…
Regardless of valve type, all stem-actuated control valves require…
A damper (otherwise known as a louvre) is a multi-element flow control…
Labwork is an essential part of any science-based curriculum. Here,…
One of the most common, and most useful, pressure measuring…
Using filter cells to eliminate wavelengths associated with…
A Safety Instrumented Function, or SIF, is one or more components…
Phasors are to AC circuit quantities as polarity is to DC circuit…
The advent of “smart” field instruments containing…
One very convenient feature of waves is that their properties are…
Steam boilers are very common in industry, principally because steam…
Learning is not merely a process of information transfer. It is first…
An important type of “accessory” relay, especially for…
A completely different way of measuring liquid level in vessels is to…
In reliability engineering, it is important to be able to quantity the…
Virtually any mass above absolute zero temperature emits…
Control valves are supposed to deliver reliable, repeatable control of…
Although it seems each model of PLC has its own idiosyncratic standard…
While the term “probability” may evoke images of…
A wise PLC programmer once told me that the first thing any aspiring…
A pneumatic controller receives a process variable (PV) signal as a…
In order for any PID controller to be practical, it must be able to do…
Valves can experience a number of problems, most of them either…
A machine in the broad sense of the word is any device designed to…
As previously defined, calibration refers to the checking and…
In order to provide an interface between the internal (digital) world…
Once while working as an instrument technician in an aluminum foundry,…
So far we have just looked at instruments that sense, control, and…
Sensors used to measure vibration come in three basic types:…
Regulating the electric power sent to an electric motor is a task…
Perhaps the simplest form of solid or liquid level measurement is with…
Recall that an exothermic chemical reaction is one that releases a net…
By definition, a source is a device delivering energy into a system,…
A great many precision instruments use the principle of balance to…
Many years ago, when I was first learning about electricity, I…
Virtually any mass above absolute zero temperature emits…
The Law of Continuity for fluids states that the product of mass…
A powerful mathematical concept useful for analyzing practically any…
The vast majority of PID controllers in service today are digital in…
These fortifications focus on human behavior rather than system design…
Electrical Resistance Resistance (\(R\)) is the dissipative opposition…
