why we use 4-20 mA to do calibration of the instruments.why we cant use 0-20 mA?

8 Answers   Emerson, IEM,

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What is 1:1 redundancy ?

0 Answers  

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what is the difference between mmhg & mmwc?. i want to calibrate a transmitter in the range of -100 to 300 mmwc. Which is the reference for calibrate the Tx,if mmwc not available?. Is it mmhg or mmho2?.

3 Answers   UPL,

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what are the diff. in servo and regulatory control?

0 Answers  

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how to measure temperature from resistance of rtd?and how to measure temp from voltage of thermocouple?is there any formulas?

3 Answers  

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why we use 3 wire rtd direct wiring for temperature measurement instead of temperature transmitter like bearing temperature

0 Answers   ABG Energy,

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Distributed control system

1 Answers   CCIE,

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why do we use 4-20 ma current why cant o-20ma

6 Answers   Southwest Cheese,

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If the on Of the DO module is off in the System cabinet, then what is the Procedure to check weather the Module is working or not.

2 Answers   Honeywell,

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i hav applied for the post of engg. in iocl so please require the past test papers fro instrumentation engg please please help me and send me the papers or tell me the pattern and type of ques asked in examination......

0 Answers  

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whats the problem will arrise if we rotate the hosing screw of the differential pressure transmitter?

1 Answers  

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send me HPCL paper

6 Answers   HPCL, Shuiba Hotel,

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