Q1) a) Draw the block diagram of a SMART TRANSMITTER with ...

P1353
Instructions to candidates :
1) Answers to the two sections should be written in separate books.
2) Neat diagrams must be drawn wherever necessary.
3) Figures to the right indicate full marks.
4) Use of logarithmic tables slide rule, Mollier charts, electronic pocket
calculator and steam tables is allowed.
5) Assume suitable data, if necessary.
Q1) a) Draw the block diagram of a SMART TRANSMITTER with differential
pressure signal as its input. Explain the function of each block. [10]
b) With suitable example distinguish between SERVO problem and
REGULATOR problem in process control. [6]
OR
Q2) a) Explain any four sensors used for pressure measurement with sketches.
[12]
b) Sensor resistance changes linearly from 100 ohm to 180 ohm as
temperature changes from 20ºC to 120ºC. Find the relationship between
resistance and temperature. [4]
Q3) a) Define the following for a control valve. [8]
i) Actuator.
ii) Positioner.
iii) Cavitation.
iv) Flashing.
b) Design a process control system that regulates light level by outputting
0-10V signal to a lighting system that provides 30-180 lux. The sensor
has a transfer function of – 120 ohm / lux with a 10 K resistance at 100
lux. The set point is 75 lux and proportional controller with a 75%
proportional band has been selected. [8]
P.T.O.

OR
Q4) a) Sketch a Digital Control valve and explain its working. Where it is used?
[8]
b) A temperature control system inputs the controlled variable as a range
0-2V. Final control element is a heater control module which requires
0-5V. Develop a PID controller for this application with K p = 2.4%/%,
K I = 9% / min / % K D = 0.7% / % / min.
The period of fastest expected change in process is estimated to be 8 sec.
[8]
Q5) a) Explain the term “Statistical Process Control”. Where it is applied? [6]
b) With a block diagram explain “Model Reference Adaptive Controller”.[6]
c) Draw the P & I Diagram of “Feed forward Control” of a Heat Exchanger.
Write the specifications of the instruments used in it. [6]
OR
Q6) a) What is a “Self Tuning Controller”? Explain with a block diagram. [6]
b) Draw the P & I Diagram for the cascade control scheme for a jacketed
CSTR (Continuously Stirred Tank Reactor) write the specifications of
the instruments used in it. [6]
c) With a block diagram explain “Programmed Adaptive Control”. [6]
Q7) a) With a block diagram explain “Feedforward Optimizing Control”. [6]
b) What are the different modelling approaches in Process Control?
Compare among them. [10]
OR
Q8) a) What is meant by “Constraint Handling”. Explain any one method for
the same. [8]
b) Explain the following terms: [8]
i) Model Predictive Control (MPC).
ii) Internal Model Control (IMC).
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Q9) a) Distinguish between “Physical Ladder Diagram” and “Programmed
Ladder Diagram”. [4]
b) Draw the event sequence and ladder diagram for a PLC system for a
“Bottle Filling Plant”. Consider all sensors as direct inputs to PLC.[12]
OR
Q10)a) Draw the block diagram of a PLC and explain the function of each block.
[6]
b) Write the important specifications of a PLC having both Analog and
Digital Inputs and outputs. [6]
c) Define the following terms with respect to a PLC.
i) I/O scan mode.
ii) Execution mode. [4]
Q11)a) Develop a supervisory control flow chart of a system to increase the set
point of a process reaction Vessel to a new value TSPNU. The temperature
set point (TSP) is to be increased in steps of 0.2% with 5 sec delay
between increases. If the pressure (P) rises above critical value (PCR),
then TSP should be decreased by 0.1% until P falls below PCR. Then
the set point increases can begin again. [10]
b) Explain the functions of the following in a Distributed Control System
(DCS). [8]
i) Local controller. ii) Co-ordinating controller.
iii) Data Links. iv) Central Information Display.
OR
Q12)Write short notes on (any three): [18]
a) Flow Totaliser. b) Alarm Annunciator.
c) Square root extractor. d) Classification of Control Panels.
e) Digital Recorders.
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