Set No. 1
Code No: RR310805
III B.Tech I Semester Supplimentary Examinations, February 2008
PROCESS INSTRUMENTATION
(Chemical Engineering)
Time: 3 hours
Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
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1. What are the different elements of a measuring instrument? Describe in detail.[16]
2. (a) How is the radiant energy measured? Explain with a neat sketch.
(b) Write short notes on Black body Radiation.
[8+8]
3. (a) Describe the construction and working of an infrared absorption spectrometer
with a figure.
(b) Explain the method of finding concentration of a component from a spectrogram.
[8+8]
4. (a) Describe the dew point method of measurement of absolute humidity.
(b) Write the principle of gas analysis by thermal conductivity.
[8+8]
5. (a) Explain with the help of neat sketches, the working principles of electric pressure gages.
(b) Mension the useful ranges of absolute for pressure measuring gauges. [10+6]
6. (a) How the level measurement in pressure vessels is carried out.
(b) Explain diaphragm box system for liquid level measurement.
[8+8]
7. (a) Name the two types of pitot tubes. Explain their construction and operation
with figures.
(b) State the advantages of a pitot tube in measurement of flow of fluids. [8+8]
8. (a) Show how an orifice is connected in a pipe line through diagrams for the
measurement of flow rate of
i. Steam
ii. Corrosive gas.
(b) Explain how viscosity compensation is provided in rotameters with appropriate sketches.
[8+8]
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Set No. 2
Code No: RR310805
III B.Tech I Semester Supplimentary Examinations, February 2008
PROCESS INSTRUMENTATION
(Chemical Engineering)
Time: 3 hours
Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆⋆⋆⋆⋆
1. What are the different elements of a measuring instrument? Describe in detail.[16]
2. Discuss the factors which influence the speed of response of a thermocouple. [16]
3. What are the basic differences between atomic emission and atomic fluorescence
spectroscopy? Why is source modulation often emplyed in atomic absorption spectroscopy?
[16]
4. (a) Describe the dew point method of measurement of absolute humidity.
(b) Write the principle of gas analysis by thermal conductivity.
[8+8]
5. With a neat diagram explain the constructional features and the working with the
circuitry of a thermocouple (thermal type) vacuum gauge
[16]
6. (a) Describe a method for continuously measuring specific gravity of liquids.
(b) Explain with a neat diagram the pneumatic balance displacement float liquid
level meter.
[6+10]
7. An orifice meter equipped with flange taps is to be installed to measure the flow
rate of crude oil to a cracking unit . The oil is flowing at 380 c through a 10 cm
pipe. The maximum flow rate of oil is 80 m3 /h . Mercury is used as manometer
liquid and glycol is used as sealing liquid in the leads. Calculate
(a) the diameter of orifice and
(b) power loss. The power loss
Data: Density of mercury =13600 kg/m3
Density of glycol = 1100 kg/m3
Reading of the manometer = 0.76 m
Discharge coefficient = 0.61.
The power loss and β are correlated by equation power loss = mβ + C.
It is given that at β=0.4, power loss is 0.81 and at β=0.6,
power loss = 0.62
[8+8]
8. It is desired to draw the instrumentation diagram for a jacketed CSTR with temperature control of exothermic reaction.
Present a detailed analysis of the procedure step wise for the construction of the
diagram and then draw the diagram.
[16]
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Set No. 3
Code No: RR310805
III B.Tech I Semester Supplimentary Examinations, February 2008
PROCESS INSTRUMENTATION
(Chemical Engineering)
Time: 3 hours
Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆⋆⋆⋆⋆
1. What are the different elements of a measuring instrument? Describe in detail.[16]
2. (a) Draw the temps in a thermocouple circuit. Discuss the methods of selecting
the Thermo Couple lead wires.
(b) What are the properties which must be considered in the selection of a thermal
well.
[10+6]
3. Why is composition analysis required in a process industry? Write briefly on the
qualitative and quantitative measurements with suitable examples. Highlight about
positive methods of composition analysis.
[16]
4. Describe the method of estimation of SO2 in industrial effluent gas.
[16]
5. With a neat diagram explain the constructional features and the working of a Bulk
Modulus pressure gauge to measure high pressures
[16]
6. (a) Describe air trap system for liquid level measurement.
(b) Explain bubbler system for liquid level measurement with a neat diagram.
[8+8]
7. A solution having specific gravity 1.15 is flowing through a 75mm diameter pipe at
a flow rate of 800litres/min. A sharp edged orifice connected to a simple mercury
manometer is installed to measure the flowrate. If the manameter shows a reading
of 40cm, what would be the orifice diameter?Assume orifice coefficient as 0.61.[16]
8. Discuss briefly the classification of methods of chemical analysis adopted in a
process industry. Highlight their unique features.
[16]
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Set No. 4
Code No: RR310805
III B.Tech I Semester Supplimentary Examinations, February 2008
PROCESS INSTRUMENTATION
(Chemical Engineering)
Time: 3 hours
Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆⋆⋆⋆⋆
1. (a) Discuss the principle, working and applications of a bimetallic thermometer.
(b) What is meant by order of instrument?
[10+6]
2. (a) Explain with a neat sketch the operation of a self balancing potentiometer
used for measuring thermocouple signals.
(b) Discuss its advantages over the direct reading millivoltmeter.
[10+6]
3. Explain the principles of operation of a non-destructive analyser (NMR) for product
indentification in petrochemical industries.
[16]
4. What is humidity? Explain its importance. Describe how moisture in fibre materials is measured by infra-red transmission technique.
[16]
5. (a) On what factors the selection of a material depends for the fabrication of a
pressure measuring gauge
(b) With a neat diagram explain the working of a Differential pressure Pneumatic
Transmitter working on a null-balance vector principle
[6+10]
6. (a) Describe in detail the level measurement in pressure vessels.
(b) Write about displacement meter for measuring specific gravity with a neat
diagram.
[8+8]
7. Describe the working principle of a V-notch and its applications. Obtain the equation used to find the flowrates using weirs.
[16]
8. Discuss briefly the classification of methods of chemical analysis adopted in a
process industry. Highlight their unique features.
[16]
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