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Prince Vegeta
Prince Vegeta • May 18, 2017

Why we use 4-20mA current signals instead of voltage?

This video has answered this question:



this question has always made me wonder, but now I got the answer. If you have other points more than the ones mentioned, please contribute.

Best regards!
Carl Ellis
Carl Ellis • Jul 2, 2017
THE Number One reason for using 4-20mA current signal is for loop powered instrumentation requiring only 2 conductors/wires from the 'control room' receiver to the field. The minimum 4mA value allows 3.5mA or 3.6mA to be used to power the instrument, without additional power conductors.

The other cited reasons are indeed advantages of a current loop over voltage, but are not the main reason 4-20mA has such widespread acceptance and useage; the main reason is loop power functionality.
Piyush Yadav
Piyush Yadav • Oct 10, 2017
Excellent explanation with in the video but i know about 4-20mA Loop powered sensors, those are mostly used for Vibration measurement for process control system...as there are many variation in instrumentation and their features that's why i uploaded a picture, you may recognise them...
Nate Pulkar
Nate Pulkar • Apr 6, 2018
What is the difference between 4-20 Current Receivers and 4-20 Current loop Receivers and which is much better for industrial standards

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