qas 0312 gmi | production technology. engineering metrology course objective students should be able...

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ENGINEERING METROLOGY QAS 0312 GMI | Production Technology

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ENGINEERING METROLOGYQAS 0312

GMI | Production Technology

ENGINEERING METROLOGYCourse Objective

Students should be able to:Explain the basic concepts of testing,

measuring and gauging procedures used in engineering.

Perform inspection of linear and angular measurement by using various types of measuring instruments and gauging methods.

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ENGINEERING METROLOGYMain Topics

1. Fundamentals of Metrology2. Basic Inspection and Procedures3. Measurement Errors4. Vernier Caliper5. Micrometer6. Mechanical Dial Indicator7. Gauge Blocks8. Surface Plate Inspection9. Instruments for Testing Angles10. Gauges11. Profile Projector12. Surface Roughness Measurement13. Measurement of Threads

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ENGINEERING METROLOGY

Assessment:CMM – 40%Metrology – 50%KQ – 10%

1. PBL 1 : 10%2. PBL 2 & Practical : 25%3. Test : 15%

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FUNDAMENTALS OF METROLOGYCHAPTER 1

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FUNDAMENTALS OF METROLOGY

Learning ObjectivesDefine the term metrologyDifferentiate between accuracy and precisionExplain the needs and functions of inspectionList the objectives of metrologyIdentify SI units and dimensionsPerform conversion of SI units

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FUNDAMENTALS OF METROLOGY

What is Metrology?Science of measurement.Concerns in correctness of measurement

Precision Accuracy

Methods and techniques of measurement based on agreed units and standards

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Robin Hood's Merry Man missed the

bull's-eye but the 3 attempts were near

each other.

Precise but inaccurate

Stone age man missed the bull's-

eye and the 3 attempts were not near each other.

Inaccurate and imprecise (unrepeatable)

Precision vs Accuracy

Precision vs Accuracy (cont)

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Olympic archer hits the bull's-eye 3

times!

Accurate and precise

American Indian's 3 attempts are near the bull's-eye, but

were not near each other.

Accurate but imprecise

FUNDAMENTALS OF METROLOGY

Why is Metrology important?Standardization in tradeEliminating technical barriers in trade,

manufacturing industry, construction etc etc.Promoting awareness to Quality Assurance

What is Inspection?Formal or Official examination of products with

the use of accurate (calibrated) measuring instruments

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To determine good or bad parts

To achieve interchangeability

To improve and develop precision measuring

instruments

Needs and Functions of Inspection

To support the manufacturing department

FUNDAMENTALS OF METROLOGY

To determine good and bad parts1. To determine the conformance of products to

specifications or requirements – important in assisting manufacturing process and assuring of quality.

2. In industry, inspection is used for selection of products whether it can be ‘accepted’ or ‘rejected’

3. To maintain the product quality – meet customer satisfaction index

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FUNDAMENTALS OF METROLOGY

To achieve Interchangeability1. Interchangeability – products should be able

to fit and mate if chosen randomly from different manufacturers

2. Examples: Screws and threads, nuts and bolts, pipes and pressure vessels, pnuematic and hydraulics fittings/valves, etc.

3. Can be achieved by means of measuring and gauging

1. Calipers, micrometers, thickness gauge, radius gauge etc

2. Plug gauge, pin gauge, ring gauge etcGMI | Production Technology

FUNDAMENTALS OF METROLOGY

To improve and develop precision measuring instruments1. Due to demands of high accuracy and

precision works or products2. Promote spirit of competition between

manufacturers to produce high quality precision parts

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FUNDAMENTALS OF METROLOGY

To support the manufacturing department1. Functions of inspection in manufacturing

industries Conformity of product’s appearance and functions Conformity of product’s dimensional specifications Conformity of product’s performance Providing data for product’s improvement analysis

Production process Manpower skills Material analysis Machines accuracy and maintainance

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OBJECTIVES OF METROLOGY

Ensure products designed – within process spec &

measuring instrument capabilities. (products)

Determine process capabilities. (processes)

Determine the measuring instrument capabilities.

(instruments)

Reduce the cost of rejects & rework. (products)

Minimize the cost of inspection. (products)

Maintenance of the accuracy of measurement.

(instruments)

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Principles of MetrologyFundamentals Units and standardsInternational System of Units (SI)

- established in 1960- by CGPM (General Conference of Weight and Measures)- e.g : Force Newton N (kgm/s2)

advantages of coherency of SI units.

same system & units of measurement regardless of industries

minimum of conversion factors

FUNDAMENTALS OF METROLOGY

Principles of Metrology Fundamentals Units and Standards

Language of measurement and must be constant worldwide

SI base units:1. Length : Meter (m)2. Mass : Kilograms (kg)3. Time : second (s)4. Current : Ampere (A)5. Thermo. Temp : Kelvin (K)6. Amount of subs. : Mole (mol)7. Luminous intensity : Candela (cd)

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FUNDAMENTALS OF METROLOGY

Principles of MetrologySI Prefixes

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Prefixes Symbol Multiplier Prefixes Symbol Multiplier

peta P 1015 deci d 10-1

tera T 1012 centi c 10-2

giga G 109 mili m 10-3

mega M 106 micro µ 10-6

kilo k 103 nano n 10-9

hecta h 102 pico p 10-12

deka da 101 femto f 10-15

FUNDAMENTALS OF METROLOGY

Principles of Metrology SI derived units:

1. Area : square meter (m2)2. Volume : cubic meter (m3)3. Velocity : meter per second (m/s)4. Acceleration : meter per square sec.

(m/s2)5. Force : Newton (N)6. Luminance : candela per square meter (cd/m2)

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FUNDAMENTALS OF METROLOGY

Convert the following unit:

 a) 0.88dm to mm:b) 200µm to Mm : c) 15mg/Gm³ to kg/cm³ :

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