In the United States, the most common language used to program PLCs is Ladder Diagram (LD), also known as…
Textbook
An electromechanical relay is an electrical switch actuated by an electromagnet coil. As switching devices,…
Textbook
Any physical location in an industrial facility harboring the potential of explosion due to the presence of…
Textbook
Some analyzers measure the composition of a process stream by directly immersing the sensing element in that…
Textbook
pH is the measurement of the hydrogen ion activity in a liquid solution. It is one of the most common forms of…
Textbook
An important design parameter of a control valve is the position it will “fail” to if it loses…
Textbook
Programmable logic controllers are essentially nothing more than special-purpose, industrial computers. As…
Textbook
Tube, like pipe, is a hollow structure designed to provide an enclosed pathway for fluids to flow. In the case…
Textbook
As we have seen, the concept of differentiation is finding the rate-of-change of one variable compared to…
Textbook
A fundamental limitation of proportional control has to do with its response to changes in setpoint and…
Textbook
A sliding-stem valve body is one where the moving parts slide with a linear motion. Some examples of…
Textbook
A fundamental principle in instrumentation system troubleshooting is that every instrument has at least one…
Textbook
One of the most important accessories for any temperature-sensing element is a pressure-tight sheath known as…
Textbook
A pressure switch is one detecting the presence of fluid pressure. Pressure switches often use diaphragms or…
Textbook
The fundamental principle of electromagnetism is that an electric current will create a magnetic field at…
Textbook
A different strategy for controlling the flow of fluid is to insert a rotary element into the flow path.…
Textbook
Three-phase AC is the dominant mode of electric power generation and distribution in modern societies.…
Textbook
Imagine a liquid-level control system for a vessel, where the position of a level-sensing float directly sets…
Textbook
Human-machine interfaces, or HMIs, are a critical part of nearly all control systems, complementing the…
Textbook
One of the fundamental laws of electric circuits is Kirchhoff’s Current Law, which states the algebraic…
Textbook
While 50 and 51 (instantaneous and time overcurrent) relay functions monitor line current magnitude and guard…
Textbook
Instrument technicians should not have to concern themselves over the programming details internal to digital…
Textbook
Disconnect Switches Disconnects are switches designed to isolate sections of a power system in case of damage…
Textbook
A much simpler alternative to continuous vibration sensors (displacement or acceleration) and monitoring…
Textbook
All masses require force to accelerate (we can also think of this in terms of the mass generating a reaction…
Textbook
An interesting parallel to the “unity fraction” unit conversion technique is something referred to…
Textbook
Using filter cells to eliminate wavelengths associated with interfering gases is called positive filtering in…
Textbook
As previously defined, calibration refers to the checking and adjustment of an instrument so that its output…
Textbook
There is much to be said for neatness of assembly in electrical signal wiring. Even though the electrons…
Textbook
Capacitive level instruments measure electrical capacitance of a conductive rod inserted vertically into a…
Textbook
When control valves operate between fully open and fully shut, they serve much the same purpose in process…
Textbook
Cyber-security seems to have its own vocabulary, ranging from unwieldy technical acronyms to slang terms…
Textbook
(Will be addressed in future versions of this book)
Textbook
Constructing PID control systems using discrete components is a fairly simple method involving operational…
Textbook
An important legacy technology for all kinds of continuous measurement is the self-balancing system. A…
Textbook
A unique form of technical diagram for describing the abstract functions comprising a control system (e.g. PID…
Textbook
Calculus has a reputation for being difficult to learn, and with good reason. The traditional approach to…
Textbook
The final element of PID control is the “D” term, which stands for derivative. This is a calculus…
Textbook
Tube, like pipe, is a hollow structure designed to provide an enclosed pathway for fluids to flow. In the case…
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
A flow switch is one detecting the flow of some fluid through a pipe. Flow switches often use…
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
The simplest form of 4-20 mA current loop is the type used to represent the output of a process controller,…
Textbook
DC electric current signals may also be used to communicate process measurement information from transmitters…
Textbook
RTDs are completely passive sensing elements, requiring the application of an externally-sourced electric…
Textbook
Most of these formulae appear in molecular chemical form rather than structural form. For example, ethanol…
Textbook
As described earlier in this chapter, calibration refers to the adjustment of an instrument so its output…
Textbook
Flow, by definition, is the passage of material from one location to another over time. So far this chapter…
Textbook
Self-balancing pneumatic instrument mechanisms are very similar to negative-feedback operational amplifier…
Textbook
A fundamental limitation of proportional control has to do with its response to changes in setpoint and…
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
The majority of flowmeter technologies operate on the principle of interpreting fluid flow based on the…
Textbook
As we have seen, feedforward control is a way to improve the stability of a feedback control system in the…
Textbook
Many liquid substances undergo a process whereby their constituent molecules split into positively and…
Textbook
Any power grid large enough to meet the demand of an entire nation must have multiple generators drawing from…
Textbook
A design-based fortification is one rooted in technical details of system architecture and functionality. Some…
Textbook
As discussed at the beginning of this chapter, instrumentation safety may be broadly divided into two…
Textbook
Facebook
Google
GitHub
Linkedin