Light is known to interact with matter in very specific ways, which…
An on/off valve is the fluid equivalent of an electrical switch: a…
Before we begin our discussion on process control, we must define a…
Pipe is a hollow structure designed to provide an enclosed pathway for…
Programmable logic controllers are built to input various signal types…
Although it seems each model of PLC has its own idiosyncratic standard…
A variety of technologies exist to measure the quantity of stored…
In contrast to quantitative tuning procedures where definite numerical…
Control strategies such as cascade, ratio, feedforward, and those…
Weight-based level instruments sense process level in a vessel by…
Measuring the flow rate of liquid through an open channel is not…
The majority of flowmeter technologies operate on the principle of…
In some process applications, it is important that the control valve…
Up until this point, we have explored various types of instrumentation…
A simple control system drawn in block diagram form looks like this:…
DC electric current signals may also be used to communicate process…
A variety of problem-solving techniques have been presented for…
Temperature measurement devices may be classified into two broad…
A 4 to 20 mA current signal represents some signal along a 0 to 100…
pH is the measurement of the hydrogen ion activity in a liquid…
Take for instance the problem of measuring fluid flow through a pipe.…
A very common method for directly controlling low flow rates of fluids…
Most pneumatic instruments use a simple but highly sensitive mechanism…
Diagnostic ability is arguably the most difficult skill to develop…
The majority of flowmeter technologies operate on the principle of…
Some problem-solving techniques are unique to quantitative problems,…
A very simple device used to measure pressure is the manometer: a…
Two extremely important principles in electric circuits were codified…
A technological advance introduced in the late 1980’s was HART,…
Finally, we arrive at the loop diagram (sometimes called a loop sheet)…
A Safety Instrumented Function, or SIF, is one or more components…
Modern DC and AC motor drives provide features useful when using…
The efficient identification and correction of instrument calibration…
Many years ago, when I was first learning about electricity, I…
Circuit breakers are the “final control elements” of the…
Recall that an exothermic chemical reaction is one that releases a net…
Electrical power grids primarily consist of three-phase AC circuits.…
A vertical column of fluid generates a pressure at the bottom of the…
Electromechanical relays may be connected together to perform logic…
