A version of thie article appeared in the February 2012 issue of Test & Measurement World. See the PDF. Many industrial systems use the 4–20-mA loop to transmit measurements from sensors to displays, ...

The 4- to 20-mA current loop is ubiquitous in the world of controls in manufacturing plants. Discrete logic, microprocessors, and microcontrollers easily cover the digital portions of control schemes, ...

Use of 4-to-20-mA current loops involves more than just a simple series connection between sensor, display, and power supply. The point where a sensor takes a measurement is, at times, many yards away ...

There is no question that there are many products on the market that use digital electronics in their design. A brief trip through your favorite computer or electronics equipment store should ...

Open-loop current sensors have a definite price advantage over closed-loop counterparts. While you can use them in drive applications where torque accuracy isn't demanding — such as pump and fan ...

Spare a moment’s pity for the process engineer, whose job it is to keep industrial automation running no matter what. These poor souls seem to be forever on call, fielding panicked requests to come to ...