RTDs are completely passive sensing elements, requiring the…
In November of 2007 a new computer virus was submitted to a virus…
“Polyphase” means “many phases,” describing a…
In some process applications, it is important that the control valve…
Disturbances in the liquid tend to complicate liquid level…
Volumes could be written about poor diagnostic technique. The…
Many liquid substances undergo a process whereby their constituent…
An interesting parallel to the “unity fraction” unit…
Learning how to tune PID controllers is a skill born of much practice.…
A number of different sensors used in instrumentation generate DC…
Light is known to interact with matter in very specific ways, which…
Some self-powered (4-wire) analog electronic transmitters are designed…
All masses require force to accelerate (we can also think of this in…
An important design parameter of a control valve is the position it…
Fieldbus devices require far more attention in their initial setup and…
Circuit breakers used in residential, commercial, and light industrial…
As previously defined, calibration refers to the checking and…
As described earlier in this chapter, calibration refers to the…
(Will be addressed in future versions of this book)
When control valves operate between fully open and fully shut, they…
Finally, we arrive at the loop diagram (sometimes called a loop sheet)…
While 50 and 51 (instantaneous and time overcurrent) relay functions…
A limitation inherent to pneumatic valve actuators is the amount of…
Perhaps the most important rule to obey when using pneumatic…
As defined previously, calibration means the comparison and adjustment…
A fundamental principle in instrumentation system troubleshooting is…
Developed by the Modicon company (the original manufacturer of the…
An important type of “accessory” relay, especially for…
Solids tend to expand when heated. The amount that a solid sample will…
A very common form of on/off valve used for pneumatic and hydraulic…
In addition to Ohm’s Law, we have a set of rules describing how…
In order for any PID controller to be practical, it must be able to do…
It is often useful to express the amplitude of an alternating quantity…
Circuit breakers used in residential, commercial, and light industrial…
A number of different sensors used in instrumentation generate DC…
An variable-area flowmeter is one where the fluid must pass through a…
When control valves operate between fully open and fully shut, they…
Mechanical pressure-sensing elements include the bellows, the…
Earlier in this chapter you were shown a model of a nitrogen atom with…
One of the most important accessories for any temperature-sensing…
The reason why a pneumatic control valve’s stem position…
