Instrumentation And Control Systems Rr321404

Set No. 1

Code No: RR321404

III B.Tech II Semester Supplimentary Examinations, Aug/Sep 2007 INSTRUMENTATION AND CONTROL SYSTEMS (Mechatronics) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Discuss briefly on the reliability of measurement systems. Explain how reliability improvement can be achieved. (b) “A pricise instrument need not be accurate” explain.

[8+8]

2. (a) How the ionization transducer is used to measure displacement? Explain the same. (b) Discuss in detail about the concept of photoelectric transducer for measuring displacement. [16] 3. (a) Explain the principle behind the temperature measurement by radiation methods. (b) Explain the working of a total radiation in pyrometer.

[16]

4. (a) Discuss the working of a Bourdon tube pressure gauge with relevant sketch and mention their merits and demerits. (b) Explain the basic principle of working of a bellow type pressure gauges. (c) Sketch the various shapes of bellow used for pressure measurement. [4+8+4] 5. Enumerate the principle of operation of the following (a) capacitative level indicator. (b) ultrasonic level measuring instrument.

[8+8]

6. (a) Explain how a vibrometer is calibrated to measure acceleration. (b) How is measurement of vibrations on large structures done? Explain the method in detail. [8+8] 7. (a) What is the need for temperature compensation in a strain gauge? How it is done. (b) Drive an equation for gauge factor for a metallic strain gauge.

[8+8]

8. (a) Distinguish between open-loop and closed loop control systems with the help of a suitable diagram. (b) Illustrate your answer using block diagram schematics. (c) Identify the system parameters and components in each case. ⋆⋆⋆⋆⋆ 1 of 1

[16]

Set No. 2

Code No: RR321404

III B.Tech II Semester Supplimentary Examinations, Aug/Sep 2007 INSTRUMENTATION AND CONTROL SYSTEMS (Mechatronics) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. Describe the principle of operation of a piezo-electric transducer. Identify the input and output of the system. [16] 2. (a) Describe the function of a stroboscope and explain how speed of a rotating shaft can be measured by single pattern and multi pattern disc. (b) Draw a neat sketch of non-contacting optical tachometer; explain the working principle of tachometer. [16] 3. (a) List all industrial thermocouples giving their elements and temperature ranges. (b) Why cold junction compensation is required? Explain an automatic cold junction compensation method. [8+8] 4. (a) Describe the reasons for the popularity of the Bourdon tube element for pressure measurement and show how the elements are constructed. (b) Describe the constructional features of i. Bellow type gauges ii. Diaphragm types gauges and show how their output signals are processing for indication. [8+8] 5. (a) List out the advantages and limitations of direct method of level measurement. (b) Describe with neat sketch the functioning of any two types of displacer type liquid level measuring instruments. [16] 6. (a) How seismic instruments are used for measuring acceleration. Explain in detail. (b) What is the importance of humidity control in process industries?

[8+4]

7. (a) Mention the important requirements for a strain gauge material. Name some of the materials used for making strain gauges. (b) How resistive strain gauges are calibrated?

[8+8]

8. (a) State the advantages of a closed loop system. (b) A constant water level is to be maintained in a boiler. Suggest a suitable automatic level control system with a block diagram and explain its working. [6+10] ⋆⋆⋆⋆⋆ 1 of 1

Set No. 3

Code No: RR321404

III B.Tech II Semester Supplimentary Examinations, Aug/Sep 2007 INSTRUMENTATION AND CONTROL SYSTEMS (Mechatronics) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Distinguish between the following. i. ii. iii. iv.

Accuracy and precision Resolution and Threshold Reproducibility and repeatability Dead zone and Hysteresis

(b) A measuring system with damping ratio ξ = 0.6 is desired to give maximum sensitivity in response to a sinusoidal input. At what value of the frequency ratio r = (w/wn ) would occur? [16] 2. (a) Explain operation of ionization transducer with a neat sketch and write the applications. (b) Describe the construction and principle of i. LVDT ii. Variable reluctance displacement transducer.

[16]

3. (a) Explain the disappearing filament pyrometer setup and explain its operation. (b) Classify the temperature measuring instruments and indicate approximate temperature range of each category. [16] 4. (a) Explain the calibration procedure of pressure measuring devices using dead weight tester. (b) Express the ratio of sensitivies of an inclined manometer to that of a simple manometer in terms of angle “theta”. For an inclined manometer six times more sensitive than a simple manometer; what should be the angle of incline. [8+8] 5. (a) Write the principle of operation of a bubbler purge and float leased level indicator. (b) With neat sketch explain any one type of ultrasonic fluid level indicator. [16] 6. (a) How seismic instruments are used for measuring acceleration. Explain in detail. (b) What is the importance of humidity control in process industries? 7. (a) What are load cells? Name the application of load cells. 1 of 2

[8+4]

Set No. 3

Code No: RR321404

(b) Describe the working principle of strain gauge bridge with neat sketch. Indicate their arrangements for measurement of torque on a circular shaft. [4+12] 8. (a) With suitable examples, bring out the advantages of closed loop systems over open loop systems. (b) Draw a block diagram of the closed loop system considered above. Also explain why negative feedback is invariably preferred in such systems. [8+8] ⋆⋆⋆⋆⋆

2 of 2

Set No. 4

Code No: RR321404

III B.Tech II Semester Supplimentary Examinations, Aug/Sep 2007 INSTRUMENTATION AND CONTROL SYSTEMS (Mechatronics) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Discuss briefly on the reliability of measurement systems. Explain how reliability improvement can be achieved. (b) “A pricise instrument need not be accurate” explain.

[8+8]

2. (a) Describe the function of a stroboscope and explain how speed of a rotating shaft can be measured by single pattern and multi pattern disc. (b) Draw a neat sketch of non-contacting optical tachometer; explain the working principle of tachometer. [16] 3. (a) What is a thermistor? Write different types. (b) What is the range of operation of thermistors? State its applications. [8+8] 4. (a) With the aid of neat sketch, explain the working principle of dead - weight type tester. (b) Discuss various types of elastic pressure sensing elements used in electrical transducers. [16] 5. (a) Write the principle of operation of a bubbler purge and float leased level indicator. (b) With neat sketch explain any one type of ultrasonic fluid level indicator. [16] 6. (a) How seismic instruments are used for measuring acceleration. Explain in detail. (b) What is the importance of humidity control in process industries?

[8+4]

7. (a) Mention the important requirements for a strain gauge material. Name some of the materials used for making strain gauges. (b) How resistive strain gauges are calibrated?

[8+8]

8. (a) Describe the working of a system which automatically turns off the street lamps at dawn and turns on at dusk. Draw a schematic diagram of the system. (b) Draw the functional diagram of thermostat controlled home heating system and identify the system parameters and components. Describe the working of the system. [16] ⋆⋆⋆⋆⋆ 1 of 1