Name : Roll No. :.... Invigilator s Signature :.. CS/B.Tech (EIE)/SEM-5/EI-501/2011-12 2011 INDUSTRIAL INSTRUMENTATION II Time Allotted : 3 Hours Full Marks : 70 The figures in the margin indicate full marks. Candidates are required to give their answers in their own words as far as practicable. GROUP A ( Multiple Choice Type Questions ) 1. Choose the correct alternatives for any ten of the following : 10 1 = 10 i) The primary standard for calibrating vacuum is a) McLeod b) Dead weight tester c) Thermocouple gauge d) Ionization gauge. ii) Gauge pressure is a) absolute pressure b) absolute pressure atmospheric pressure c) atmospheric pressure d) atmospheric pressure absolute pressure. 5004 [ Turn over
iii) One torr is defined as a) one mm Hg b) one inch Hg c) one atmosphere d) one kilopascal. iv) Which of the following flowmeters has the highest discharge coefficient? a) Orifice plate b) Venturi tube c) Flow nozzle d) None of these. v) An example of a positive displacement flowmeter is a) Orifice meter b) Rotary vane type meter c) Turbine type meter d) Ultrasonic flowmeter. vi) The basic principle of float type level sensor is a) force balance b) motion balance c) energy balance d) none of these. vii) Which of the following is a temperature sensor excellent liner characteristic? a) RTD b) Thermocouple c) Silicon base IC chip d) Radiation pyrometer. viii) Electromagnetic flowmeters are used to measure the a) flow of non-conducting fluid b) flow of non-conducting fluid in a metallic pipe c) flow of non-conducting fluid in a plastic pipe d) wind velocity. 5004 2
ix) Dead weight tester is used for a) testing dead weight b) producing high pressure c) measuring process pressure accurately d) calibration pressure instrument. x) In case of a capacitive level measurement capacitance will... with the increase of level. a) increase b) decrease c) remain same d) no relation between level and capacitance. xi) Pt-100 RTD means temperature bulb having a) 0 ohm at 100 C b) 100 ohm at 100 C c) 100 ohm at 0 C d) 0 ohm at 0 C. xii) In radiation level detector which radiation is generally used? a) Beta particles b) Alpha particles c) Gamma rays d) Neutrons. 5004 3 [ Turn over
GROUP B ( Short Answer Type Questions ) Answer any three of the following. 3 5 = 15 2. Draw a labelled sketch diagram of C-type Bourdon tube pressure gauge and explain its principle of operation. 3. a) 3-wire RTD connection is advantageous over 2-wire RTD connection. Explain. b) What do you mean by thermowell? 3 + 2 4. a) Distinguish between gauge, absolute and vacuum pressure. b) What are the selection criteria of manometric fluid? 3 + 2 5. What do you mean by discharge coefficient? Differentiate between laminar flow and turbulent flow. 2 + 3 6. Describe with neat sketch, the working principle of an ultrasonic level indicator. 5004 4
GROUP C ( Long Answer Type Questions ) Answer any three of the following. 3 15 = 45 7. a) Sketch and describe the principle of capacitive type level measurement. b) Describe the level measurement technique of high pressure tank using sight glass or gauge glass with suitable diagram. c) Explain how displacer can be used for level measurement. d) Describe with a neat sketch, the construction and working of a radiation level indicator. 5 + 3 + 4 + 3 8. a) Describe with neat sketch, the working principle of electromagnetic flowmeter. What are its advantages and disadvantages? b) What are the different tapping positions for fluid flow line in orifice flowmeters? 5004 5 [ Turn over
c) What is vena-contracta position? d) Define Reynolds number. State its significance in determining fluid characteristics. 6 + 3 + 2 + 4 9. a) What is meant by cold junction compensation? Describe one technique for cold junction compensation. b) Why is lead compensation not required in thermistor for temperature measurement? c) Describe the operating principle of bimetallic thermometer. ( 2 + 5 ) + 3 + 5 10. a) Explain, with a neat sketch, the construction and working of a strain gauge pressure transducer. b) How is dead weight tester used for pressure instrument calibration? c) Explain with a neat sketch, the construction and working of a McLeod gauge. d) Explain the advantage of inclined manometer with suitable diagram. 3 + 5 + 5 + 2 5004 6
11. Write short notes on any three of the following : 3 5 a) Radiation pyrometer b) Vortex shedding flowmeter c) D/P transmitter d) Thermocouple e) Bicolour level gauge. 5004 7 [ Turn over