why we use cascade control and feed foreword control in 3 element control of boiler drum ?what is feed forward and cascade control system ?

0 Answers   Visa Steel,

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What are the different modes of a contollogix family processor? How they work?

3 Answers   Honeywell, Siemens,

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what is burner management system?

2 Answers   Alstom,

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please can any one tell me clearly about pid tuning i am confusing about this .how to tune pid easly?

0 Answers   HP, Siemens,

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what is the working principle of vortex flowmeter

9 Answers   Essar,

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what is mean by process control?

4 Answers  

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We have a Yokogawa Micro-XL DCS, which is having around 300 I/O, but whenever there is any wire gets grounded in field, the 24v supply to all loops gets dipped & all the indications at DCS goes to IOP(shows input open), at present we have fixed 500mA fuses in all the lines but which does not working. Does it required to replace with lower amps fuse, then how much or is there any other solution for this.

2 Answers  

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what is the input to be given in digital flow meter during the the calibration time?

0 Answers   ONGC,

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i feel sq. pipe is better than round pipe pls give comment for this. advance thanks for reply

3 Answers  

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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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How can we say that accuracy of measurement increases by using 3 or 4 wire RTD? because for example: If resistance of RTD element is say r ohms and Resistance of the cable from transmitter to RTD is R ohms And if 4 wire RTD is used, ____._____________________ R ohms | |_____._____________________ R ohms / \ / r ohms \ \ | |______.__________________ R Ohms | |_______._________________ R ohms Then the actual resistance measured will be: Total = r + R/2 + R/2 = r +R Ohms Note: r+R instead of r ohms. hence error

2 Answers  

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what is upstream and downstream in liquid flow?

6 Answers   Thermax,

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