Mechanical Measurement And Metrology - Jun 2014
Mechanical Engineering (Semester 4)
TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) Explain objectives of Metrology.(3 marks) 1 (b) What are the various possible sources of errors in measurement? Define static error and explain any two static errors with example.(7 marks) 1 (c) Describe with neat sketch "Imperial standard Yard".(4 marks) 2 (a) Describe working principle and construction of Vernier micrometer with neat sketch.(7 marks)
Answer any two question from Q2 (b) or Q2 (c)
2 (b) With the help of neat sketch describe the working principle and construction of an optical comparator with its advantages and limitations.(7 marks)
2 (c) (i) Write applications and limitations of angle gauges.(3 marks)
2 (c) (ii) The following observations were obtained while checking angle of tapered piece on one side with the help of two discs (Rollers), slip gauge and dial indicator.
Diameter of larger disc = 40 mm
Diameter of smaller disc = 24 mm
Slip gauge placed between the discs = 30 mm
The dial indicator shows no variation when traversed along the surface of the piece placed over the discs. Draw the sketch of the set up and find angle of taper.(4 marks)
Answer any two question from Q3 (a), (b) or Q3 (c), (d)
3 (a) Define the following terms for Screw thread:
ii) Minor Diameter
v) Flank angle
vi) Helix angle(3 marks) 3 (a) With neat sketch explain the construction and working of bourdon tube pressure gauge and also write merits and demerits of its.(7 marks) 3 (b) Explain the measurement of effective diameter for internal screw threads with neat sketch(4 marks) 3 (b) Explain in brief the following with neat sketch
i) Prony brake dynamometer and
ii) Rope brake dynamometer(7 marks) 3 (c) Explain three wire method to measure the effective diameter of given screw thread with neat sketch.(7 marks)
Answer any two question from Q4 (a), (b) or Q4 (c), (d)
4 (a) Explain Parkinson gear tester with neat sketch.(4 marks) 4 (b) A spur gear of 8 mm module has 50 teeth calculate following proportion: Pitch circle diameter, Addendum and Dedendum, Tooth working height and base pitch. Assume clearance to be 0.25 module. Spur gear has pressure angle of 20°.(3 marks) 4 (c) With neat sketch describe the construction working of Tomlinson surface roughness tester with its advantages and disadvantages.(7 marks) 4 (c) Describe the construction and working of resistance temperature Detector (RTD) with its advantages and disadvantages.(7 marks) 4 (d) Explain the various modes of measurements with two examples.(7 marks)
Answer any two question from Q5 (a), (b) or Q5 (c), (d)
5 (a) Define Flatness and describe a method to find out the flatness of a surface plate.(7 marks)
5 (b) Define squareness. Explain with neat sketch the following methods or measuring the squareness.
i) Indicator method
ii) Auto collimator method(7 marks) 5 (c) Explain surface texture and elements of surface roughness.(7 marks) 5 (d) Explain with neat sketch the principle, construction and working of Johansson Mikrokator.(7 marks)