Rr320302-metrology

Set No. 1

Code No: RR320302

III B.Tech Supplimentary Examinations, Aug/Sep 2008 METROLOGY (Mechanical Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Explain the terms: Basic size; Zero line; lower and upper deviations. Draw a conventional diagram to represent these terms for a shaft and hole pair of interference fit. (b) The hole and shaft assembly of 30mm nominal size have tolerances specified −0.04 as 30+0.02 −0.000 mm for hole and 30−0.07 mm for shaft. Determine i. ii. iii. iv. v. vi.

Maximum and minimum clearance (interference) attainable Allowance Hole and shaft tolerances Fundamental deviation MML for shaft and hole Type of fit. Sketch these values on a conventional diagram.

[8+8]

2. (a) Describe the selection of minimum number of slip gauges for a dimension of 29.759mm from M112 set. What care of slip gauges is essential ? (b) Describe the working principle and uses of Lever type dial test indicator. [8+8] 3. Discuss various methods of taper measurement of plug and ring gauges.

[16]

4. (a) Differentiate between limit plug gangue and ring gauge. (b) Design general type GO and NO-GO gauges for components having 75 H9/d10 fit. The basic size falls in the diameter range of 50-80mm. The fundamental deviation for ‘d’ shaft=(-16 D0.41 ) microns. The multipliers for 9 and 10 grades are 40 and 63. Take wear allowance as 10% of gauge tolerance. Sketch the gauges with values. [6+10] 5. Describe the working principle of NPL Flatness interferometer with a sketch. What are the fringe patterns obtainable in case of tapered surfaces. [16] 6. (a) Enumerate various direct instrument methods for measurement of surface finish. (b) Describe surface measurement with inspection by comparison methods. [6+10] 7. (a) What are the advantages and disadvantages of mechanical comparators. (b) Explain the working principle of mechanical-optical comparator. 1 of 2

[6+10]

Set No. 1

Code No: RR320302

8. (a) Elucidate the Effective diameter measurement by two wire method (b) Explicate gear metrology of spur gears with reference to i. Lead ii. pitch

[8+8] ⋆⋆⋆⋆⋆

2 of 2

Set No. 2

Code No: RR320302

III B.Tech Supplimentary Examinations, Aug/Sep 2008 METROLOGY (Mechanical Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Explain the terms: Limits (upper & lower)of tolerance and fit. Sketch the conventional diagram to represent these terms for a shaft and a hole. (b) For each of the following shaft and hole pair, calculate shaft tolerance, hole tolerance and analyze whether the pair is i. Clearance fit ii. Transition fit iii. Interference fit. Pair 1: Hole:- 30+0.02 Shaft:- 30−0.04 +0.00 mm +0.005 mm +0.06 Pair 2: Hole:- 30+0.00 mm Shaft:- 30−0.03 +0.05 mm +0.05 +0.08 Pair 3: Hole:- 30+0.00 mm Shaft:- 30+0.05 mm Sketch the three fits on the same zero line.

[8+8]

2. (a) Discuss the advantages of digital measuring instruments over others. What are progressive errors in micrometers? (b) Describe the uses and advantages of dial indicators. 3. Discuss various methods of taper measurement of plug and ring gauges.

[8+8] [16]

4. (a) Discuss the applicability of different allowances in design of gauges . (b) Design and sketch the ‘workshop gauge’, ‘inspection gauge’ and general type +0.02 of ‘GO and NO GO’ plug gauges for checking holes of 50−0.001 mm. Assume wear allowance is 10% of gauge tolerance. [6+10] 5. (a) Explain with a sketch the working of Microptic Auto Collimator . (b) Elucidate the working principle of optical projector and optical flats.

[8+8]

6. (a) What are various orders of geometrical irregularities on surfaces ? How these are classified? (b) Describe with a neat sketch the construction , principle and operation of Tomlinson surface meter. [6+10] 7. (a) What are the advantages, uses and disadvantages of electrical comparators. (b) Explain the following alignment tests on lathe: i. True running of locating cylinder of main spindle. ii. True running of taper socket in main spindle. 8. (a) Elucidate various methods of measuring 1 of 2

[8+8]

Set No. 2

Code No: RR320302 i. Thread form ii. Thread angle by vernier protractor.

(b) Explicate gear metrology of spur gears with reference to Tooth thickness by chordal thickness method. [8+8] ⋆⋆⋆⋆⋆

2 of 2

Set No. 3

Code No: RR320302

III B.Tech Supplimentary Examinations, Aug/Sep 2008 METROLOGY (Mechanical Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Explain terms : Interchangeability and selective assembly. Enumerate the differences between them. (b) Determine and sketch the limits of tolerance and allowance for a 25mm shaft and hole pair designated H8 − d9 . The basic size lies in the range of 18-30mm. The multipliers for grades 8 and 9 are 25 and 40 respectively. The fundamental deviation for ‘d’ shaft is (-16 D0.44 ) microns. [8+8] 2. (a) Describe the selection of minimum number of slip gauges for a dimension of 29.759mm from M112 set. What care of slip gauges is essential ? (b) Describe the working principle and uses of Lever type dial test indicator. [8+8] 3. (a) Enunciate the use of sine bar for checking the angles of large sized components (b) The angle of wedge shaped block is being checked with 100mm Sine bar. With slip gauges of 26.867mm height at one end of Sine bar, the dial gauge readings at each end of the work piece vary by 0.06mm, the gauge block end being low. If the work piece is 30mm long what should be the next height of the gauge block tried ? Also calculate the angle of the work piece? [8+8] 4. (a) Differentiate between workshop gauges and inspection gauges. (b) Design general type GO and NO-GO gauges for components having 45 H7/g8 fit. The basic size falls in the diameter range of 30-50mm. The fundamental deviation for ‘g’ shaft=(-2.5 D0.34 ) microns. The multipliers for 7 and 8 grades are 16 and 25. Take wear allowance as 10% of gauge tolerance. Sketch the gauges with values. [6+10] 5. What are the uses of optical flats? Describe testing of optical flats for flatness. [16] 6. (a) Describe surface roughness evaluation by profilo-graph (b) Define terms: RMS value; CLA value.

[10+6]

7. (a) Differentiate among measuring instrument, gauge and comparator. What are the uses of a comparator? (b) Describe the working principle of Reed type mechanical comparator with special reference to amplification ranges available. [6+10] 8. (a) Elucidate the Effective diameter measurement by two wire method (b) Explicate gear metrology of spur gears with reference to 1 of 2

Set No. 3

Code No: RR320302 i. Lead ii. pitch

[8+8] ⋆⋆⋆⋆⋆

2 of 2

Set No. 4

Code No: RR320302

III B.Tech Supplimentary Examinations, Aug/Sep 2008 METROLOGY (Mechanical Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Explain the terms: Limits (upper & lower)of tolerance and fit. Sketch the conventional diagram to represent these terms for a shaft and a hole. (b) For each of the following shaft and hole pair, calculate shaft tolerance, hole tolerance and analyze whether the pair is i. Clearance fit ii. Transition fit iii. Interference fit. Pair 1: Hole:- 30+0.02 Shaft:- 30−0.04 +0.00 mm +0.005 mm −0.03 Pair 2: Hole:- 30+0.06 mm Shaft:30 +0.00 +0.05 mm +0.05 +0.08 Pair 3: Hole:- 30+0.00 mm Shaft:- 30+0.05 mm Sketch the three fits on the same zero line.

[8+8]

2. (a) What are slip gauges ? What are their uses? (b) What are the requirements of a good dial indicator? What are advantages of it? [8+8] 3. Discuss various methods of taper measurement of plug and ring gauges.

[16]

4. (a) Explicate the classification of plain limit gauges. (b) Design general type GO and NO-GO gauges for components having 25 H8/f9 fit. The basic size falls in the diameter range of 18-30mm. The fundamental deviation for ‘f’ shaft=(-5.5 D0.4 ) microns. The multipliers for 8 and 9 grades are 25 and 40. Take wear allowance as 10% of gauge tolerance. Sketch the gauges with values. [6+10] 5. (a) What are the limitations and uses of optical flats? (b) Describe the working principle of interferometer with a neat sketch.

[6+10]

6. (a) Stylus type instruments are widely used despite several disadvantages-Explain (b) The heights of peaks and valleys of 20 successive points on a surface are 45, 30, 42, 25, 40, 25, 35, 24, 35, 18, 42, 34, 45, 31, 40, 30, 41, 24, 42, 18 microns respectively, measured over a length 20 mm, Determine CLA and RMS values of roughness surface. [8+8] 7. (a) Enumerate various characteristics of a good comparator. (b) Explain the working of sigma comparator with special reference to cross strip lever in detail. [6+10] 1 of 2

Set No. 4

Code No: RR320302

8. (a) “ Measurement of effective diameter by three wires is more accurate than any other method” - Explain. (b) State various sources of errors in manufacture of gears. ⋆⋆⋆⋆⋆

2 of 2

[8+8]