Most people reading this book have likely had the experience of adjusting water temperature using two hand…
Textbook
There are many process control applications in the industry where it is desirable to have multiple control…
Textbook
In some process applications, it is important that the control valve be able to completely stop fluid flow…
Textbook
One of the most common, and most useful, pressure measuring instruments in industry is the differential…
Textbook
A sliding-stem valve body is one where the moving parts slide with a linear motion. Some examples of…
Textbook
Sometimes we encounter a diversity of instrument signal standards in one control system. Such is the case with…
Textbook
Fluid pressure exerts force on any surface area it contacts, as described by the formula \(F = PA\). One…
Textbook
As previously defined, calibration refers to the checking and adjustment of an instrument so that its output…
Textbook
Current is the name we give to the motion of electric charges from a point of high potential to a point of low…
Textbook
A simple control system drawn in block diagram form looks like this: Information from the measuring device…
Textbook
The reason why a pneumatic control valve’s stem position corresponds linearly to the amount of air…
Textbook
All masses require force to accelerate (we can also think of this in terms of the mass generating a reaction…
Textbook
Valves can experience a number of problems, most of them either preventable or repairable. These problems can…
Textbook
An on/off valve is the fluid equivalent of an electrical switch: a device that either allows unimpeded flow or…
Textbook
To show a practical process example, let’s examine three diagrams for a compressor control system,…
Textbook
A different strategy for controlling the flow of fluid is to insert a rotary element into the flow path.…
Textbook
Perhaps the most important rule of controller tuning is to know the process before attempting to adjust the…
Textbook
A limitation inherent to pneumatic valve actuators is the amount of air flow required to or from the actuator…
Textbook
A great many precision instruments use the principle of balance to measure some quantity. Perhaps the simplest…
Textbook
Diagnostic ability is arguably the most difficult skill to develop within a student, and also the most…
Textbook
The simple PLC ladder diagram (LD) commands consist of contacts and coils, arranged in sequences that mimic…
Textbook
Valve actuators provide force to move control valve trim. For precise positioning of a control valve, there…
Textbook
Disturbances in the liquid tend to complicate liquid level measurement. These disturbances may result from…
Textbook
Multiple accessories exist for pressure-sensing devices to function optimally in challenging process…
Textbook
As we have seen, the concept of differentiation is finding the rate-of-change of one variable compared to…
Textbook
By definition, a source is a device delivering energy into a system, while a load is a device extracting…
Textbook
An important design parameter of a control valve is the position it will “fail” to if it loses…
Textbook
Visualizing the actions of P, I, and D tuning parameters using graphs is extremely useful in predicting the…
Textbook
Circuit breakers used in residential, commercial, and light industrial service are self-tripping devices: they…
Textbook
A proximity switch is one detecting the proximity (closeness) of some object. By definition, these switches…
Textbook
An electric motor is often used as a discrete control element in a control system if driving a pump, conveyor…
Textbook
A vertical column of fluid generates a pressure at the bottom of the column owing to the action of gravity on…
Textbook
The dispersion of visible light into its constituent colors goes all the way back to the 17th century with…
Textbook
The digital multimeter (DMM) is quite possibly the most useful tool in the instrument technician’s…
Textbook
The vast majority of modern process transmitters (both analog and digital) come equipped with a feature known…
Textbook
The electrical conductivity of liquids is an important analytical measurement in many industrial processes.…
Textbook
The term “grid” refers to the conductors and equipment interconnecting power sources to power…
Textbook
The key to understanding how three-phase electric motors work is to have an accurate mental picture of the…
Textbook
In addition to Ohm’s Law, we have a set of rules describing how voltages, currents, and resistances…
Textbook
Human-machine interfaces, or HMIs, are a critical part of nearly all control systems, complementing the…
Textbook
Facebook
Google
GitHub
Linkedin