Introduction to Precision Metrology

1. Introduction to Precision Metrology

2. General Comments Precision tools – delicate – treat them with respect Set them down carefully – preferably something soft Wood, linoleum – avoid metals, ceramics, glass Check gauging surfaces – clean off and set to zero When finished – wipe clean and return to storage box Use rag with a drop or two of oil With care these tools will last for years If mis-treated they become worthless in days

3. General Comments cont’d Using precision tools is somewhat complex Result – concentration on details – not bigger picture Keep plastic ruler handy – double check measurements More mixture of English and metric units Measure twice – cut once

4. What you will do in lab Use some precision tools to measure sample parts Gain a feel for use of the tool and its capabilities Use some tools in order of increasing resolution Gain a feeling for tool features that increase resolution Get an understanding of the types of tools available Tools used are generally available for mechanical inspection Learn about ISO 5460, techniques to measure features Set ups to measure specific features called out on drawings Examples, flatness, straightness, roundness

5. Calipers – from ISO 3599

6. Outside mircometers – ISO 3611

7. Dial indicators – test and long travel

8. Gauge or Jo Blocks – ISO 3650

9. Gauge blocks con’t

10. Angle gauge blocks

11. Inside micrometers

12. Sine plate or bar

13. Inspection of mechanical parts Part is held against datums called out on drawing Indicator is slid along part for checking features with a spatial extent Indicator reading must remain inside tolerance band

14. Use of “V” blocks

15. Measuring parallelism