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Why do we go for 4-20mA? why not other standara?

Answer Posted / jb

In long distance wire if some wire are broken then at the
receiver end there will be current value 0. If we take 0-20
standard in that case it will be difficult to know that the
current value is actually 0 or its 0 because of broken wire.
but in case of 4-20 it the the signal is in off state then
at the receiver end we will have current value 4 and in
case of broken wore we will have current value 0.

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