Perhaps the most valuable skill an instrument technician can possess is the ability to efficiently diagnose…
Textbook
When control valves operate between fully open and fully shut, they serve much the same purpose in process…
Textbook
Phasors are to AC circuit quantities as polarity is to DC circuit quantities: a way to express the…
Textbook
The two “process variables” we rely on most heavily in the field of electrical measurement and…
Textbook
The simple PLC ladder diagram (LD) commands consist of contacts and coils, arranged in sequences that mimic…
Textbook
Perhaps the most basic and necessary protective relay function is overcurrent: commanding a circuit breaker to…
Textbook
Data-processing modules within FF systems are known as function blocks. Sometimes these blocks serve merely to…
Textbook
RTDs are completely passive sensing elements, requiring the application of an externally-sourced electric…
Textbook
There are many process control applications in the industry where it is desirable to have multiple control…
Textbook
Light is known to interact with matter in very specific ways, which may be exploited as a means of measuring…
Textbook
As we have seen, the concept of differentiation is finding the rate-of-change of one variable compared to…
Textbook
The efficient identification and correction of instrument calibration errors is an important function for…
Textbook
As we have seen, feedforward control is a way to improve the stability of a feedback control system in the…
Textbook
Constructing PID control systems using discrete components is a fairly simple method involving operational…
Textbook
The vast majority of PID controllers in service today are digital in nature. Microprocessors executing PID…
Textbook
An extremely important topic in engineering is that of transfer functions. Simply defined, a transfer function…
Textbook
One of the fundamental laws of electric circuits is Kirchhoff’s Current Law, which states the algebraic…
Textbook
Human-machine interfaces, or HMIs, are a critical part of nearly all control systems, complementing the…
Textbook
Three-phase AC is the dominant mode of electric power generation and distribution in modern societies.…
Textbook
The transformer is one of the most important components in all of AC circuitry. Principally used to…
Textbook
In order to provide an interface between the internal (digital) world of a computer and the external (analog)…
Textbook
Many liquid substances undergo a process whereby their constituent molecules split into positively and…
Textbook
Electromechanical relays may be connected together to perform logic and control functions, acting as logic…
Textbook
Process measurements are often of an analog nature: the temperature of a furnace, the rate of fluid flow…
Textbook
Like so many other industrial data networks, FOUNDATION Fieldbus is an “unswitched” or…
Textbook
An important legacy technology for all kinds of continuous measurement is the self-balancing system. A…
Textbook
Calculus has a reputation for being difficult to learn, and with good reason. The traditional approach to…
Textbook
The following animation shows how the “rotating” magnetic field of a three-phase AC induction…
Textbook
For better or worse, there are no fewer than three different forms of PID equations implemented in modern PID…
Textbook
A pneumatic controller receives a process variable (PV) signal as a variable air pressure, compares that…
Textbook
A fluid is any substance having the ability to flow: to freely change shape and move under the influence of a…
Textbook
Capacitive level instruments measure electrical capacitance of a conductive rod inserted vertically into a…
Textbook
Disturbances in the liquid tend to complicate liquid level measurement. These disturbances may result from…
Textbook
In the United States, the ANSI and IEEE organizations have standardized a set of numerical codes referring to…
Textbook
Capacitance Any two electrical conductors separated by an insulating medium possess the characteristic called…
Textbook
Perhaps the most important rule of controller tuning is to know the process before attempting to adjust the…
Textbook
A form of protection against faults on long-distance power lines is called distance relaying, so named because…
Textbook
A level switch is one detecting the level of liquid or solid (granules or powder) in a vessel. Level switches…
Textbook
The dispersion of visible light into its constituent colors goes all the way back to the 17th century with…
Textbook
A variety of technologies exist to measure the quantity of stored material in a vessel. For liquid…
Textbook
Facebook
Google
GitHub
Linkedin