problem1)a) describe with neat sketch the working of Johannson Mikrokrator.
b) Define the following: Dead band, resolution, linearity, allowance.
c) What do you mean by a drunken thread?
problem 2)a) describe briefly Pnuematic comparator and its types and derive the equation for pneumatic sensitivity and overall magnification.
b) describe with a neat sketch the method of checking flatness using N.P.L Interferometer
problem3)a) describe the method of determining the effective diameter of a screw thread using a screw thread micrometer. In measuring the effective diameter of a 24mm x 3mm pitch metric plug screw gauge the average readings were taken as below
Micrometer reading over the standard and wires.....12.9330mm
Micrometer reading over the gauge and wires.....12.1100mm
Diameter of cylindrical standard.....22.0010mm
Diameter of wires.....1.7320mm
find out the effective diameter.
b) List four advantages and four limitations of Pneumatic comparator.
problem4)a) A pneumatic comparator has a linear characteristic given by P/P= 0.5 M/C + 1.1 over the range P/P from 0.6 to 0.8. The control jet is 1 mm diameter and the measuring orifice is a 0.5 mm diameter hole.
(i) The range of linear measurement.
(ii) The measuring head, pneumatic, and overall sensitivities if the
back-pressure gauge has a deflection of 25 mm for 1 kN/m2 pressure change and the supply pressure is constant at 200 kN/m2 (2 bar) gauge pressure.
b) describe the method of using the following types of gauges with a sketch
i) Taper ring gauge
ii) Progressive Rib type Snap gauge
problem5)a) Define effective diameter of a screw thread. What is the difference between effective diamter and pitch diameter in screw threads? With a neat sketch expalin a method to measure the external threads?
b) describe the constructional details and working of a Sigma comparator with a sketch.
problem6)a) Determine the limits of the hole and shaft pair designated as Ø 18 G11 js10. (The fundamental deviation of g shaft is given by 2.5 D0.44 with appropriate sign).
b) Define the following with respect to limits, fits and tolerances in a labeled sketch
ii) Fundamental deviation
iii) Tolerance zone
v) upper and lower deviation.