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

Answer Posted / parag pathak

Signal can be sent via voltage, but as signal will be drop
if it has to sent long distance,but current signal will not
not lost,so we are preffering current signal over voltage
signal. secondly we can use 0-20 mA instead of 4-20 mA, but
then we cannot know whether it is dead zero or 0 reading.
Now once any manufacturer make any standard it is accepted
throughout so that new Instrument will also be compatible
with that system.

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