An important design parameter of a control valve is the position it will “fail” to if it loses…
Textbook
Every flow-measuring instrument exploits a physical principle to measure the flow rate of fluid stream.…
Textbook
Self-balancing pneumatic instrument mechanisms are very similar to negative-feedback operational amplifier…
Textbook
Perhaps the most confusing aspect of discrete sensors is the definition of a sensor’s normal status.…
Textbook
In order for any PID controller to be practical, it must be able to do more than just implement the PID…
Textbook
Control valves are supposed to deliver reliable, repeatable control of process fluid flow rate over a wide…
Textbook
Suppose we wished to measure the rate of propane gas flow through a hose to a torch: Flowmeters appropriate…
Textbook
The reason why a pneumatic control valve’s stem position corresponds linearly to the amount of air…
Textbook
Volumes could be written about poor diagnostic technique. The following mistakes are not intended to comprise…
Textbook
Valve actuators provide force to move control valve trim. For precise positioning of a control valve, there…
Textbook
There are many process control applications in the industry where it is desirable to have multiple control…
Textbook
To better understand the design and operation of self-balancing pneumatic mechanisms, it is helpful to examine…
Textbook
As a general rule, high achievement only takes place in an atmosphere of high expectations. Sometimes these…
Textbook
Labwork is an essential part of any science-based curriculum. Here, much improvement may be made over the…
Textbook
Measuring the flow rate of liquid through an open channel is not unlike measuring the flow rate of a liquid…
Textbook
Multiple accessories exist for pressure-sensing devices to function optimally in challenging process…
Textbook
Electromechanical relays may be connected together to perform logic and control functions, acting as logic…
Textbook
Regulating the electric power sent to an electric motor is a task performed by high-speed switching…
Textbook
Programmable logic controllers are essentially nothing more than special-purpose, industrial computers. As…
Textbook
By definition, a source is a device delivering energy into a system, while a load is a device extracting…
Textbook
It is possible to convey electrical power and communicate analog information over the same two wires using 4…
Textbook
Regardless of valve type, all stem-actuated control valves require some form of seal allowing motion of the…
Textbook
Binary patterns are not just able to represent numerical values. Given a standardized code, they may represent…
Textbook
In modern industry, the most popular form of field-level signal transmission for variable industrial…
Textbook
It is often useful to express the amplitude of an alternating quantity such as voltage or current in terms…
Textbook
A simple control system drawn in block diagram form looks like this: Information from the measuring device…
Textbook
DC electric current signals may also be used to communicate process measurement information from transmitters…
Textbook
As described earlier in this chapter, calibration refers to the adjustment of an instrument so its output…
Textbook
AC induction motors are based on the principle of a rotating magnetic field produced by a set of stationary…
Textbook
The reason why a pneumatic control valve’s stem position corresponds linearly to the amount of air…
Textbook
The fundamental principle of electromagnetism is that an electric current will create a magnetic field at…
Textbook
A sliding-stem valve body is one where the moving parts slide with a linear motion. Some examples of…
Textbook
The electrical conductivity of liquids is an important analytical measurement in many industrial processes.…
Textbook
A pneumatic controller receives a process variable (PV) signal as a variable air pressure, compares that…
Textbook
Process measurements are often of an analog nature: the temperature of a furnace, the rate of fluid flow…
Textbook
An important type of “accessory” relay, especially for legacy electromechanical protective relays,…
Textbook
There is much to be said for neatness of assembly in electrical signal wiring. Even though the electrons…
Textbook
In the United States, the most common language used to program PLCs is Ladder Diagram (LD), also known as…
Textbook
Three-phase AC is the dominant mode of electric power generation and distribution in modern societies.…
Textbook
The vast majority of modern process transmitters (both analog and digital) come equipped with a feature known…
Textbook
Data-processing modules within FF systems are known as function blocks. Sometimes these blocks serve merely to…
Textbook
Given the ability of pressurized fluids to transmit force over long distances, it is not surprising that many…
Textbook
The term “grid” refers to the conductors and equipment interconnecting power sources to power…
Textbook
It is possible to convey electrical power and communicate analog information over the same two wires using 4…
Textbook
What is Calibration? To calibrate an instrument means to check and adjust (if necessary) its response so the…
Textbook
Atom: the smallest unit of matter that may be isolated by chemical means. Particle: a part of an atom,…
Textbook
In some process applications, it is important that the control valve be able to completely stop fluid flow…
Textbook
PID control can be a confusing concept to understand. Here, a brief summary of each term within PID (P. I, and…
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
There is much to be said for neatness of assembly in electrical signal wiring. Even though the electrons…
Textbook
Visualizing the actions of P, I, and D tuning parameters using graphs is extremely useful in predicting the…
Textbook
A great many precision instruments use the principle of balance to measure some quantity. Perhaps the simplest…
Textbook
A variety of technologies exist to measure the quantity of stored material in a vessel. For liquid…
Textbook
Learning from reading printed text is a kind of problem-solving activity it is own right. The problem is how…
Textbook
Regardless of valve type, all stem-actuated control valves require some form of seal allowing motion of the…
Textbook
In a manually-controlled process, a human operator directly actuates some form of final control element…
Textbook
A flow switch is one that detects the flow of some fluid through a pipe. Flow switches often use…
Textbook
Steam boilers are very common in industry, principally because steam power is so useful. Common uses for steam…
Textbook
Calculus has a reputation for being difficult to learn, and with good reason. The traditional approach to…
Textbook
Facebook
Google
GitHub
Linkedin