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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I am new in work for 1 of our project we have some instrument in BOM including Pressure, Temp. and so on, I also noticed some objects like pressure switch process HOOK UP; which I don't know what does "HOOK UP" mean here.

3 Answers  

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the pump holds on run indication into the dcs and filed local control panel remote push button condition operaton wrong like when the push button pushing conditions the pump is off and the push button release condition the pump is on totally opposite condition . And control room inside give the stop command into dcs just 1secon relay engage and again normal condition. How can I slove

0 Answers  

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Dear friends, I have a question: We work on a project which has some boilers to provide steam for desalination unit. The boiler area is safe and the only hazard source is the fuel lines of boilers. I want to know according to NFPA standard which type of instrument should be selected on the fuel line: Eex Type or Non-Eex type? Thanks in advance

2 Answers  

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What is the use of temprature compensation?

0 Answers  

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which are types of orifice tap ?

2 Answers  

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why 4-20 mA in covection system?

3 Answers  

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HOW CREATED LP & HP PRESURES IN DRUM FOR DRUM LEVEL MEASUREMENT!

0 Answers  

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hello dear i have faced problem in drum level transmitter. the problem is when i engrize the meter meter shows 100% but the actual level 40 or something plz suggest me

7 Answers  

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what is your eligibility criteria for freashers?

0 Answers   Satyam,

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I faced several time siemens ps2 positioner automatically getting Chang in it's set point direction after auto calibration  So is there any causes biside this or  any  permissives ?

0 Answers  

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.how does CSADA systems display the process variable value?

2 Answers   Empower,

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