PID control can be a confusing concept to understand. Here, a brief summary of each term within PID (P. I, and…
Textbook
Learn about Modbus function codes, the structure of Modbus message packets, and the various types of channels used to transmit Modbus telegrams between controllers.
Textbook
Electromechanical relays may be connected together to perform logic and control functions, acting as logic…
Textbook
An electric motor is often used as a discrete control element in a control system if driving a pump, conveyor…
Textbook
Perhaps the most confusing aspect of discrete sensors is the definition of a sensor’s normal status.…
Textbook
In addition to directly performing logic functions, electromechanical relays may also be used as interposing…
Textbook
(Will be addressed in future versions of this book)
Textbook
One of the most important accessories for any temperature-sensing element is a pressure-tight sheath known as…
Textbook
The reason why a pneumatic control valve’s stem position corresponds linearly to the amount of air…
Textbook
Steam boilers are very common in industry, principally because steam power is so useful. Common uses for steam…
Textbook
The following photograph shows a large air blower in a wastewater treatment facility equipped with a…
Textbook
One of the great benefits of digital technology is the ability to communicate vast amounts of information over…
Textbook
The vast majority of PID controllers in service today are digital in nature. Microprocessors executing PID…
Textbook
A simple control system drawn in block diagram form looks like this: Information from the measuring device…
Textbook
The simple PLC ladder diagram (LD) commands consist of contacts and coils, arranged in sequences that mimic…
Textbook
A 4 to 20 mA current signal represents some signal along a 0 to 100 percent scale. Usually, this scale is…
Textbook
The advent of “smart” field instruments containing microprocessors has been a great advance for…
Textbook
Multiple accessories exist for pressure-sensing devices to function optimally in challenging process…
Textbook
Programmable logic controllers are essentially nothing more than special-purpose, industrial computers. As…
Textbook
The purpose of a control valve actuator is to provide the motive force to operate a valve mechanism. Both…
Textbook
The following animation shows a rotating phasor in three-dimensional form. The phasor rotates in a complex…
Textbook
A different strategy for controlling the flow of fluid is to insert a rotary element into the flow path.…
Textbook
“Feedforward” is a rather under-used control strategy capable of managing a great many types of…
Textbook
Imagine a major marathon race, where hundreds of runners gather in one place to compete. When the starting gun…
Textbook
Earlier in this chapter you were shown a model of a nitrogen atom with a dense nucleus (comprised of protons…
Textbook
One of the most important accessories for any temperature-sensing element is a pressure-tight sheath known as…
Textbook
The efficient identification and correction of instrument calibration errors is an important function for…
Textbook
Weight-based level instruments sense process level in a vessel by directly measuring the weight of the vessel.…
Textbook
Much of our knowledge about atomic structure comes from experimental data relating the interaction between…
Textbook
Perhaps the most valuable skill an instrument technician can possess is the ability to efficiently diagnose…
Textbook
In reliability engineering, it is important to be able to quantity the reliability (or conversely, the…
Textbook
Instrument technicians should not have to concern themselves over the programming details internal to digital…
Textbook
Suppose we wished to measure the rate of propane gas flow through a hose to a torch: Flowmeters appropriate…
Textbook
“Radio” systems use electromagnetic fields to communicate information over long distances through…
Textbook
Using filter cells to eliminate wavelengths associated with interfering gases is called positive filtering in…
Textbook
There are many process control applications in the industry where it is desirable to have multiple control…
Textbook
The very purpose of physics is to quantitatively describe and explain the physical world in as few terms as…
Textbook
A unique form of technical diagram for describing the abstract functions comprising a control system (e.g. PID…
Textbook
The vast majority of modern process transmitters (both analog and digital) come equipped with a feature known…
Textbook
Perhaps the simplest form of solid or liquid level measurement is with a float: a device that rides on the…
Textbook
Facebook
Google
GitHub
Linkedin