Answer / s.farhan haider rizvi

becouse we can't get 100% sure our device are working
properly or not working.we know that 0 MA DEAD condition
and 4 MA live dead condition,

Answer / anzal

to know actual zero or dead zero

Answer / harold

4 ma is the live zero

Answer / alok kajla

we use 4ma lowest value because it shows that devide is in working condition and at lowst level. if we take 0ma as starting point then we can't differ the situation that device giving lowest value or device is off condition.

Answer / azhar mottur

o know actual zero or dead zero

Answer / abhishek rathore

4mamp current signal consider as 0% if sensor or wireing fault then signal goes to 0mamp controller or operator understand signal fault mode goes.1,2,3mA not consider because bydeafault 1-3% signal present in the systembut 4mA not goes to signal bydefault .so we are consider 4-20mA signal

Answer / ragu.j

All transmitter are working in 1 to 5volts. So, now we
calculate the V=IR. That means Volt equal to
current*Resistance.
for eg :
calculate to(4ma*250ohms)=1000 milli volt or 1volt
and(20ma*250ohms)=5000 millivolts or 5volts.

Answer / fred good

we use up to 3.9 ma for powering instruments

Answer / urooj

4mA is the leakage current that flows in the circuit even
when the least voltage is appied ..

Answer / s hasini

TO MEASURE THE INSTRUMENTAL ERROR

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hii my name is sujith...i am preparing for HPVL GET 2010... so ,,,pls help me by send any previous questions or material to my site.....(Msujith_12@in.com) thank q

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When doing a liquid seal on a differential flow transmitter , most of the time the sealing liquid will be heavier then the process fluid. For wich application will the sealing liquid be lighter than the process fluid if transmitter is mounted below the process line.

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