An extremely important topic in engineering is that of transfer functions. Simply defined, a transfer function…
Textbook
Programmable logic controllers are essentially nothing more than special-purpose, industrial computers. As…
Textbook
In addition to directly performing logic functions, electromechanical relays may also be used as interposing…
Textbook
Most pneumatic instruments use a simple but highly sensitive mechanism for converting mechanical motion into…
Textbook
Fieldbus devices require far more attention in their initial setup and commissioning than their analog…
Textbook
The next level of detail is the Process and Instrument Diagram, or P&ID. Here, we see a “zooming…
Textbook
Light has long been used as a long-range signaling medium. While communication by light through open air is…
Textbook
An important legacy technology for all kinds of continuous measurement is the self-balancing system. A…
Textbook
Any physical location in an industrial facility harboring the potential of explosion due to the presence of…
Textbook
In order to provide an interface between the internal (digital) world of a computer and the external (analog)…
Textbook
In addition to Ohm’s Law, we have a set of rules describing how voltages, currents, and resistances…
Textbook
Imagine a liquid-level control system for a vessel, where the position of a level-sensing float directly sets…
Textbook
Like so many other industrial data networks, FOUNDATION Fieldbus is an “unswitched” or…
Textbook
There are several different methods useful for causing an AC induction motor to brake, or slow down: DC…
Textbook
A completely different way of measuring liquid level in vessels is to bounce a traveling wave off the surface…
Textbook
The disadvantages of pneumatic instruments are painfully evident to anyone familiar with both pneumatic and…
Textbook
Perhaps the simplest form of solid or liquid level measurement is with a float: a device that rides on the…
Textbook
“Radio” systems use electromagnetic fields to communicate information over long distances through…
Textbook
Data-processing modules within FF systems are known as function blocks. Sometimes these blocks serve merely to…
Textbook
While 50 and 51 (instantaneous and time overcurrent) relay functions monitor line current magnitude and guard…
Textbook
Capacitors store energy in electric fields, proportional to the square of voltage. Inductors store energy in…
Textbook
A completely different way of measuring liquid level in vessels is to bounce a traveling wave off the surface…
Textbook
The efficient identification and correction of instrument calibration errors is an important function for…
Textbook
Capacitance Any two electrical conductors separated by an insulating medium possess the characteristic called…
Textbook
Any power grid large enough to meet the demand of an entire nation must have multiple generators drawing from…
Textbook
Perhaps the most basic and necessary protective relay function is overcurrent: commanding a circuit breaker to…
Textbook
A chemical reaction resulting in a net release of energy is called exothermic. Conversely, a chemical reaction…
Textbook
An electromechanical relay is an electrical switch actuated by an electromagnet coil. As switching devices,…
Textbook
Disturbances in the liquid tend to complicate liquid level measurement. These disturbances may result from…
Textbook
Control strategies such as cascade, ratio, feedforward, and those containing limit and selector functions can…
Textbook
In the United States, the ANSI and IEEE organizations have standardized a set of numerical codes referring to…
Textbook
Imagine a liquid-level control system for a vessel, where the position of a level-sensing float directly sets…
Textbook
The transformer is one of the most important components in all of AC circuitry. Principally used to…
Textbook
The Law of Continuity for fluids states that the product of mass density (\(\rho\)), cross-sectional pipe area…
Textbook
As we have seen, the concept of integration is finding the accumulation of one variable multiplied by another…
Textbook
As we have seen, the concept of differentiation is finding the rate-of-change of one variable compared to…
Textbook
One of the fundamental laws of electric circuits is Kirchhoff’s Current Law, which states the algebraic…
Textbook
In addition to Ohm’s Law, we have a set of rules describing how voltages, currents, and resistances…
Textbook
In order for any PID controller to be practical, it must be able to do more than just implement the PID…
Textbook
Electromechanical relays may be connected together to perform logic and control functions, acting as logic…
Textbook
A hand switch is exactly what the name implies: an electrical switch actuated by a person’s hand motion.…
Textbook
There is much to be said for neatness of assembly in electrical signal wiring. Even though the electrons…
Textbook
A technological advance introduced in the late 1980’s was HART, an acronym standing for Highway…
Textbook
Given the ability of pressurized fluids to transmit force over long distances, it is not surprising that many…
Textbook
Every programmable logic controller must have some means of receiving and interpreting signals from real-world…
Textbook
As a general rule, high achievement only takes place in an atmosphere of high expectations. Sometimes these…
Textbook
A chemical reaction resulting in a net release of energy is called exothermic. Conversely, a chemical reaction…
Textbook
The advent of “smart” field instruments containing microprocessors has been a great advance for…
Textbook
Atom: the smallest unit of matter that may be isolated by chemical means. Particle: a part of an atom,…
Textbook
Linearity of Measurement Instruments The purpose of calibration is to ensure the input and output of an…
Textbook
The concepts of calibration (trimming) and ranging are often difficult for new students of instrumentation to…
Textbook
The dispersion of visible light into its constituent colors goes all the way back to the 17th century with…
Textbook
A form of protection against faults on long-distance power lines is called distance relaying, so named because…
Textbook
The fundamental principle of electromagnetism is that an electric current will create a magnetic field at…
Textbook
A level switch is one detecting the level of liquid or solid (granules or powder) in a vessel. Level switches…
Textbook
The following animation shows a rotating phasor in three-dimensional form. The phasor rotates in a complex…
Textbook
Sometimes we encounter a diversity of instrument signal standards in one control system. Such is the case with…
Textbook
The Law of Continuity for fluids states that the product of mass density (\(\rho\)), cross-sectional pipe area…
Textbook
Perhaps the most important rule to obey when using pneumatic instruments is to maintain clean and dry…
Textbook
All masses require force to accelerate (we can also think of this in terms of the mass generating a reaction…
Textbook
Facebook
Google
GitHub
Linkedin