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?



Answer Posted / nilesh karpe

Rajesh & BM has ansered 1 to 12 questions:
13.first check the stroke of the valve.ie. fully open &
then full close(for checking smooth operation).
ZERO CALLIBRATION:
at full close see the demand of i/p is 4MA.& output for
this is 0.2 KG/cm2. if not adjust through ZERO pot in i/p.
SPAN CALLLIBRATION:
fully open the valve.at this time the dmd of i/p should
20MA.at this time o/p supply air should 1KG/CM2.if not
adjust the span pot in i/p.
REPEAT THE ABOVE STEPS IN TILL ZERO & SPAN READINGS
MATCH.CHECHK INTERMIDIATE POSITIONS i.e. for dmd signal of
4,8,12,16& 20MA.FOR LINEARITY CHACKING.

Is This Answer Correct ?    23 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What are the charcterstics of a P&ID controller block for Governor speed raise or lower for a load sharing functionality between 4 Gas turbines in droop mode.

2495


I was working on calibrating turbidity transmitters endress+hauser at effluent polishing plant.We calibrated using NTU buffers.What happened is that when we immersed the sensor, everytime we raise and lower the sensor gradually, the reading will vary.my question is that is there any specifications on what is the required distance from the bottom of the container with buffer to the face of the sensor?Is it ok to install the sensor in a medium which has turbulence specially if bubbles are present?

1730


Explain bernoulli’s theorem. State its application.

682


what is interlock system and why we use of this?

1445


What is the use of double seated valve?

733






hello sir/madam, I,Subramanian need 5yrs placement papers of officer trainee of Instrumentation technology.pls send to this mail id mani_nxtgen@yahoo.co.in please do the needful. with regards, subramanian.v

1766


POSSITIVE PULSE IS APPLIED TO AN INVERTER INPUT.THE TIME FROM THE LEADING EDGE OF THE INPUT TO THE LEADING EDGE OF THE OUTPUT IS 10 ns. THE TIME FROM THE TRAILING EDGE OF THE INPUT TO THE TRYLING EDGE OF THE OUTPUT IS 8 ns. WHAT ARE THE VALUES OF tPLH and tPHL?

1757


1.what is controller proportional gain 2.what is the controller intergral action time. 3.A proportional plus derivative controller that has a proportional band of 20% and a derivative action time of 0.1 minutes. Construct the shape of the output waveform for the triangular input if the input rises and falls at the rate of 4 units per minute.

2217


Why boiler chimney area  oxyden sensor fixing? 

2042


Draw a complete P&ID of a flow suction tank indicating all control & protection equipment. Indicate all its inlets and outlets. Explain the controls for this system

1099


what is commisioning procedure,2)what is is the main work in commisioning in the field tx to dcs, plz send me detail

1854


How many are the types of instrument cables in terms of No. of pair.

1703


What is the purpose of bypass valve across AS valve.

1656


What is the cascade control

989


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

1755