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 / ritheesh kumar.p
why not take 0-20mA the reason for this is when 0 is
considered as minimum value then we will get 0 as output
when no signal is coming,when the instrument is not working
or there is any fault in it we get 0.inorder to ensure that
the instrument works we choose 4-20mA as standard output
value.4 corresponds to no signal from the instrument. 20mA
is the maximum value because below 20mA we will be able to
avoid schocks and short circuits
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