Multiple accessories exist for pressure-sensing devices to function optimally in challenging process…
Textbook
Self-balancing mechanisms consisting solely of a baffle/nozzle detector coupled to a feedback bellows, while…
Textbook
A sliding-stem valve body is one where the moving parts slide with a linear motion. Some examples of…
Textbook
A very common form of on/off valve used for pneumatic and hydraulic systems alike is the solenoid valve. A…
Textbook
So far we have just looked at instruments that sense, control, and influence process variables. Transmitters,…
Textbook
Perhaps the simplest form of solid or liquid level measurement is with a float: a device that rides on the…
Textbook
Up until this point, we have explored various types of instrumentation diagram, each one making reference to…
Textbook
As previously defined, calibration refers to the checking and adjustment of an instrument so that its output…
Textbook
All masses require force to accelerate (we can also think of this in terms of the mass generating a reaction…
Textbook
In some process applications, it is important that the control valve be able to completely stop fluid flow…
Textbook
Some analyzers measure the composition of a process stream by directly immersing the sensing element in that…
Textbook
There are many process control applications in the industry where it is desirable to have multiple control…
Textbook
When a high-energy photon strikes an atom, it may eject one of the lower-level electrons from its shell,…
Textbook
A vertical column of fluid generates a pressure at the bottom of the column owing to the action of gravity on…
Textbook
The following collection of photographs chronicles the complete disassembly of a Fisher E-body globe valve…
Textbook
Disconnect Switches Disconnects are switches designed to isolate sections of a power system in case of damage…
Textbook
A simple control system drawn in block diagram form looks like this: Information from the measuring device…
Textbook
One of the most common, and most useful, pressure measuring instruments in industry is the differential…
Textbook
Sometimes we encounter a diversity of instrument signal standards in one control system. Such is the case with…
Textbook
A Safety Instrumented Function, or SIF, is one or more components designed to execute a specific…
Textbook
Diagnostic ability is arguably the most difficult skill to develop within a student, and also the most…
Textbook
A great many precision instruments use the principle of balance to measure some quantity. Perhaps the simplest…
Textbook
In the United States, the most common language used to program PLCs is Ladder Diagram (LD), also known as…
Textbook
An important design parameter of a control valve is the position it will “fail” to if it loses…
Textbook
Electrical power grids primarily consist of three-phase AC circuits. This means most power lines (transmission…
Textbook
In addition to Ohm’s Law, we have a set of rules describing how voltages, currents, and resistances…
Textbook
Regulating the electric power sent to an electric motor is a task performed by high-speed switching…
Textbook
Mechanical pressure-sensing elements include the bellows, the diaphragm, and the bourdon tube. Each of these…
Textbook
Once while working as an instrument technician in an aluminum foundry, a mechanic asked me what it was that I…
Textbook
A different strategy for controlling the flow of fluid is to insert a rotary element into the flow path.…
Textbook
It is possible to convey electrical power and communicate analog information over the same two wires using 4…
Textbook
Impedance in a series circuit is the orthogonal sum of resistance and reactance: \[Z = \sqrt{R^2 + (X_L -…
Textbook
The concepts of calibration (trimming) and ranging are often difficult for new students of instrumentation to…
Textbook
Process analyzers measure the concentration of specific substances for the purpose of measuring and/or…
Textbook
Two extremely important principles in electric circuits were codified by Gustav Robert Kirchhoff in the year…
Textbook
It is often useful to express the amplitude of an alternating quantity such as voltage or current in terms…
Textbook
Coy, John J. et. al. (December 2012) Sampled graphic illustrations from his NASA Reference Publication…
Textbook
Many liquid substances undergo a process whereby their constituent molecules split into positively and…
Textbook
The simple PLC ladder diagram (LD) commands consist of contacts and coils, arranged in sequences that mimic…
Textbook
Filled-bulb systems exploit the principle of fluid expansion to measure temperature. If a fluid is enclosed in…
Textbook
There is much to be said for neatness of assembly in electrical signal wiring. Even though the electrons…
Textbook
Facebook
Google
GitHub
Linkedin