Answer / prashant sharma

A servomechanism, usually shortened to just servo, is a
device used to provide mechanical control at a distance.A
servo can be used at a remote location to proportionally
follow the angular position of a control knob. The
connection between the two is not mechanical, but
electrical or wireless.Servos are commonly electrical or
partially electronic in nature, using an electric motor as
the primary means of creating mechanical force, though
other types that use hydraulics, pneumatics or magnetic
principles are available.
A proportioning valve is a valve
that relies on the laws of fluid pressure to distribute
input forces to one or more output lines. A proportioning
valve can increase or decrease forces for each output,
depending on the cross-sectional surface areas of those
output lines.

I want to measure level under vaccum by using DP Tx and vaccum vary between -500 to -670 mmHg and process fluid is accetic anhydride if consider process fluid density 1 kg/cm2. how to calibrate Tx ? consider level is 0 to 100 Cm.

1 Answers   CCC,

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i have level transmitter -400 to 0 range for steam drum application but i am unable to calibrate if installation of lt below lower tap what will be the effect ? and as per std wht is location of lt ,above lower tapping or below

1 Answers  

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1. What means HART communicator / where it is used / how to use it? 2. Types of Thermocouples and its temperature ranges / output of thermocouple? 3. Types of RTDs and its temperature ranges / output of RTD? 4. Idea about Temperature Transmitters? 5. Difference between Analog and Digital signals? 6. Difference between “2 wire” and “4 wire” system / instruments? 7. Difference between “Potential” and “Potential free” contact? 8. Types of flow meters / transmitters? 9. Types of level transmitters? 10. Difference between “Power/Control” cable and “Instrument” cable? 11. What means “shield” and “screen” in cables / how it is useful? 12. Draw a schematic of closed loop circuit of flow / level / pressure / temperature? 13. Idea about calibration of Control valve / positioned / I/P? 14. How to bypass a digital/analog signal in PLC/DCS by hardwire and software?

6 Answers   JSL,

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what is the electrical operation procedure for switching on 27.6MVA electric furnace.

0 Answers   Jindal,

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What is the use of temprature compensation?

0 Answers  

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how to know the URL and LRL for steam drum level and why the calibration range is in negative ?

1 Answers   JSW, Samsung,

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1. How can leveltrol be installed in steam drum for measuring the level of steam drum?

1 Answers   Fischer,

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what is the difference between E/P positioner and I/P positioner in control valve , in which application the respective positioner are used in.

1 Answers   ABB,

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wht is snap action switch?where it is used?is there any diff between snap action switch and normal pressure switch?

1 Answers   ONGC,

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why k factor is important to know in flow transmitter. if we don,t know k factor what will be issue we can face .

1 Answers   Flour Tech Engineers (P) Ltd,

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why OPC server is used in DCS?

2 Answers  

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What is Fieldbus?

3 Answers   NSL,

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