Unit 1 Introduction to Metrology, Linear and Angular Measurement

8 lecture hours

• objectives and concept of metrology
• Need of inspection
• methods of measurement
• Classification and selection of measuring instruments and systems
• precision and errors in measurement
• System of measurement
• Material Standard
• Wavelength Standards
• Subdivision of standards
• Line and End standards
• Classification of standards and Traceability
• calibration of End bars
• Slip gauges- Indian standards on slip gauge
• method of selection of slip gauge
• stack of slip gauge
• adjustable slip gauge
• wringing of slip gauge
• care of slip gauge
• slip gauge accessories
• problems on building of slip gauges (M87
• Measurement of angles- sine bar, sine center
• angle gauges
• optical instruments for angular measurements
• Auto collimator-applications for measuring straightness and squareness

Unit 2 System of Limits, Fits, Tolerance and Gauging

8 lecture hours

• Definition of tolerance
• Specification in assembly
• Principle of interchangeability and selective assembly
• limits of size
• Indian standards
• concept of limits of size and tolerances
• definition of fits
• hole basis system
• shaft basis system
• types of fits and their designation (IS 919-1963)
• geometric tolerance
• Classification of gauges
• brief concept of design of gauges (Taylor's principles)
• Wear allowance on gauges
• Types of gauges-plain plug gauge
• ring gauge
• snap gauge
• limit gauge and gauge materials
• Comparators: Functional requirements
• mechanical- Johnson Mikrokator
• sigma comparators
• dial indicator
• electrical- principles
• Pneumatic- back pressure gauges
• Solex comparators and optical comparators- Zeiss ultra-optimeter

Unit 3 Measurement of screw thread and gear

8 lecture hours

• Terminology of screw threads
• measurement of major diameter
• minor diameter
• angle and effective diameter of screw threads by 2-wire and 3- wire methods
• best size wire
• Screw thread gauges
• Tool maker's microscope
• Gear tooth terminology
• tooth thickness measurement using constant chord method
• addendum comparator method and base tangent method
• measurement of pitch
• run out, and involute profile
• Gear roll tester for composite error

Unit 4 Measurement systems and basic concepts of measurement methods

• significance of measurement
• generalized measurement system
• definitions and concept of accuracy
• loading effect
• system responsetime delay
• Errors in measurement
• classification of errors
• transfer efficiency
• primary and secondary transducers
• electronic transducers
• advantages of each type transducers
• Intermediate modifying and terminating devices: Mechanical systems
• inherent problems
• electrical intermediate modifying devices
• input circuitry
• ballast circuit
• electronic amplifiers
• Terminating devices
• Cathode ray oscilloscope
• Advances in metrology: Basic concepts of lasers
• advantages of lasers
• laser interferometers
• Basic concepts of Coordinate Measuring Machines constructional features
• applications. 8 Program Name: Bachelor of Engineering Level: UG Branch: Mechanical Engineering Subject Code: BE04000181 Subject Name: Mechanical Measurement & Metrology

Unit 5 Force, Torque, Pressure, Strain and temperature Measurement

10 lecture hours

• Direct methods and indirect method
• force measuring instruments Torque measuring instruments
• Types of dynamometers
• Absorption dynamometer
• Prony brake and rope brake dynamometer, and power measuring instruments
• Pressure measurement
• pitot tube
• pressure gauges
• pressure transducers
• use of elastic members
• Bridgeman gauge
• McLeod gauge
• Pirani gauge
• Theory of strain gauges
• electrical resistance strain gauge
• preparation and mounting of strain gauges
• gauge factor
• methods of strain measurement
• Temperature Compensation
• Wheatstone bridge circuit
• orientation of strain gauges for force and torque
• Strain gauge based load cells and torque sensors
• Resistance thermometers
• law of thermocouple
• materials used for construction
• optical pyrometer

Unit 6 Metrology of Surface finish

3 lecture hours

• Surface Metrology Concepts and terminology
• Analysis of surface traces
• Specification of surface Texture characteristics, and Method of measuring surface finish: Stylus system of measurement
• Stylus probe instruments
• Wave length
• frequency and cut off, other methods for measuring surface roughness: Pneumatic method
• Light Interference microscopes
• Mecrin Instruments