An electric motor is often used as a discrete control element in a…
Imagine a liquid-level control system for a vessel, where the position…
The fundamental principle of electromagnetism is that an electric…
At the next OSI Reference Model layer (layer 4) is a set of protocols…
In some process applications, it is important that the control valve…
Converting between disparate units of measurement is the bane of many…
The Law of Mass Conservation states that matter can neither be created…
Binary patterns are not just able to represent numerical values. Given…
A powerful mathematical concept useful for analyzing practically any…
I remember first learning about the world-wide Internet, and wondering…
A great many chemical composition measurements may be made indirectly…
Learning how to tune PID controllers is a skill born of much practice.…
Sensors used to measure vibration come in three basic types:…
A damper (otherwise known as a louvre) is a multi-element flow control…
The reason why a pneumatic control valve’s stem position…
“As to methods there may be a million and then some, but…
A completely different way of measuring liquid level in vessels is to…
A hand switch is exactly what the name implies: an electrical switch…
Lipták, Béla G. et al., Instrument Engineers’ Handbook – Process…
Modern DC and AC motor drives provide features useful when using…
Since we often use electricity to convey energy from one location to…
A level switch is one detecting the level of liquid or solid (granules…
RTDs are completely passive sensing elements, requiring the…
A different strategy for controlling the flow of fluid is to insert a…
The most popular form of signal transmission used in modern industrial…
The fundamental principle of electromagnetism is that an electric…
Light is known to interact with matter in very specific ways, which…
Converting between disparate units of measurement is the bane of many…
Perhaps the most basic and necessary protective relay function is…
First, let us review some of the properties of differentials and…
A pneumatic controller receives a process variable (PV) signal as a…
So far we have just looked at instruments that sense, control, and…
Programmable logic controllers are essentially nothing more than…
A limit switch detects the physical motion of an object by direct…
In contrast to quantitative tuning procedures where definite numerical…
An interesting parallel to the “unity fraction” unit…
Impedance in a series circuit is the orthogonal sum of resistance and…
Measuring the flow rate of liquid through an open channel is not…
The vast majority of modern process transmitters (both analog and…
As we have seen, the concept of integration is finding the…
