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why we take 4 to 20 mA as out put of every instrument like
pressure transmittre ?why we cant take 0 to 20mA as output?
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Answer Posted / vinoth s
If we use 0 to 20ma, then 0 will be the minimum value and 20
will be maximum value.. In case if there is any problem in
the transmitter or in the cables, we get the value 0 but we
think it as a minimum value..we cant able to know that
there is problem in transmitter.. In order to overcome these
constraints, we went for LIVE ZERO concept as 4ma.
0 ma will be consider as DEAD ZERO.
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