ர 00000CH403121902 Pages: 2

Reg No.: Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

Seventh Semester B.Tech Degree Examination (Regular and Supplementary), December 2020

Course Code: CH403
Course Name: PROCESS INSTRUMENTATION

Max. Marks: 100 Duration: 3 Hours
PARTA
Answer any two full questions, each carries 15 marks. Marks
1 a) Explain different functions of an instrument. (5)

b) List out and explain different dynamic characteristics of an instrument. Also (7)
explain how the dynamic behaviour of an instrument can be determined.
c) Differentiate sensors and transducers with suitable examples. (3)
2 a) With a neat figure, explain the principle and working of mercury in glass (8)
thermometer. In some cases, dry nitrogen gas under pressure is filled above the
mercury bore in a mercury thermometer, explain the purpose of this.
b) Explain the principle and working of an optical pyrometer with a neat figure. (7)
3 9) Explain the terms accuracy, reproducibility and sensitivity of an instrument. (6)
b) Enumerate and explain any four sources of errors and precautions to be taken (6)
while using temperature measuring instruments.
c) Describe the principle of working of resistance thermometers. List out the (3)
commonly used sensing element materials in resistance thermometers.
PART ‏تا‎
‎Answer any two full questions, each carries 20 marks.
4 a) With a neat figure, explain the principle and working of McLeod gauge. Derive (12)
the expression for finding pressure.
b) Explain the working of bellows used for pressure measurement with a neat (8)
figure.

5 a) Explain the principle, components and working of rotameter with a neat sketch. (10)
b) Describe the principle of working of quantity meters, head meters, variable area (10)
flow meter and open channel flow meters with two examples each.
6 a) Explain principle of operation of piezoelectric sensors. List the advantages and (10)
disadvantages of piezoelectric sensors.
b) Explain the working of venturi meter with a neat figure. List out its advantages (10)
and disadvantages.
PART C
Answer any two full questions, each carries 15 marks.
7 a) Explain the thermal drying method used to determine the moisture content. (12)
Explain the precautions to be taken, advantages and limitations of this method.

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