“Feedforward” is a rather under-used control strategy…
It is possible to convey electrical power and communicate analog…
The purpose of a control valve actuator is to provide the motive force…
DC electric current signals may also be used to communicate process…
Finally, we arrive at the loop diagram (sometimes called a loop sheet)…
Some self-powered (4-wire) analog electronic transmitters are designed…
Any power grid large enough to meet the demand of an entire nation…
Some problem-solving techniques are unique to quantitative problems,…
As described earlier in this chapter, calibration refers to the…
Every programmable logic controller must have some means of receiving…
Shown here is a partial listing of principles applied in the subject…
The vast majority of PID controllers in service today are digital in…
A damper (otherwise known as a louvre) is a multi-element flow control…
Diagnostic ability is arguably the most difficult skill to develop…
Imagine a major marathon race, where hundreds of runners gather in one…
A fundamental principle in instrumentation system troubleshooting is…
Learning how to tune PID controllers is a skill born of much practice.…
What is Calibration? To calibrate an instrument means to check and…
The digital multimeter (DMM) is quite possibly the most useful tool in…
“As to methods there may be a million and then some, but…
Self-balancing mechanisms consisting solely of a baffle/nozzle…
Visualizing the actions of P, I, and D tuning parameters using graphs…
Regulating the electric power sent to an electric motor is a task…
Modern analog-to-digital converters are phenomenally accurate,…
Finally, we arrive at the loop diagram (sometimes called a loop sheet)…
While 50 and 51 (instantaneous and time overcurrent) relay functions…
An electric motor is often used as a discrete control element in a…
Perhaps the most confusing aspect of discrete sensors is the…
Valve actuators provide force to move control valve trim. For precise…
A special type flowmeter suited for powdered or granular solids is the…
In the United States, the most common language used to program PLCs is…
An extremely important topic in engineering is that of transfer…
Impedance in a series circuit is the orthogonal sum of resistance and…
Diagnostic ability is arguably the most difficult skill to develop…
A wise PLC programmer once told me that the first thing any aspiring…
Most pneumatic instruments use a simple but highly sensitive mechanism…
In this section I will show screenshots from a process loop simulation…
Perhaps the most important rule of controller tuning is to know the…