why 4 to 20 ma ,why not 0 to 20 or 3 to 15 or anything

Answer Posted / rajubisen1984

i read all answer of all abobe. max of u r correct for 0-20
mA but why not 3-15 mA
this is only bcoz max. of currenr transducer have the max
linearity in the range of 4-20.
again question raise that why higher limit is 20 mA
this is done because we need a large span range for good
analysis and 21.4 mA is the max. range of linearity in the
same way in lower side min range is 2.8 mA so its better to
use 4-20 mA

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