1. AURT225667A Use and maintain measuring equipment – Part 1
AUR30405 CERTIFICATE III IN AUTOMOTIVE MECHANICAL TECHNOLOGY
AURT225667A Use and maintain measuring equipment – Part 1
Introductory explanation of scope of resource

2. Introduction to measuring
Measuring must be done accurately.
Measure size, fit, clearance, pressure, temperature or other specification.
Importance of measuring and checking in the automotive field
Measure and adjust –
spark plug gaps
valve clearances
fuel pressures
what else?

3. Measuring accurately
Measuring tools can easily be damaged. Damaged tools are inaccurate.
Don’t drop or mis-handle them.
Check them regularly for accuracy.
To measure accurately:
• Handle measuring tools correctly
• Select measuring tools that are accurate for the work
• Check measuring tool is reading accurately.
Importance of accurate measuring, caring for measuring instruments.

4. Measuring equipment steel rule straight edge feeler gauge
outside calliper
micrometer
Range of measuring instruments covered in this Power Point (Part 1). Temperature, Pressure & Electrical measurements are covered in Part 2.
vernier calliper
dial indicator

5. Manual lifting safety
Measuring sometimes involves working with heavy or awkward machinery or parts eg cylinder heads, cylinder blocks and crankshafts.
Use stands, chocks, or “V” blocks to stop parts moving.
When lifting or moving heavy parts - ask for help, or use a crane or lifting equipment.
Safety precautions when lifting heavy objects.

6. Flat Feeler Gauge Hardened steel blades of different thicknesses
Each blade marked with its size in millimeters and/or inches.
Useful for:
measuring small slots or grooves
measuring clearances of machinery, eg valve or tappet clearance.
Description and application of flat feeler gauges.

7. Wire feeler gauge Has several wires, each with a different thickness
Designed to check and adjust spark plug gaps
Has a gap adjuster, to bend the earth electrode on the spark plug.
Description and application of wire-type feeler gauges.

8. Straight edge Made from a thick wide strip of alloy steel
Hardened and ground to form two parallel flat edges
Usually between 150mm to l000mm in length.
Can be used for checking the flatness of a surface.
Used to measure the gap between the straight edge and a surface eg on a cylinder head.
Description and application of straight edge and feeler gauges.

9. Steel rules Care Used for general measurements
Graduated in millimeters and centimeters.
Care
Handle carefully.
The zero end of the rule must be
Kept in perfect condition to maintain accuracy.
Introducing calipers and rules- description and care of rules

10. Measuring with a steel rule
Generally measure to an accuracy of 1 mm.
Some measure to an accuracy of 0.5mm.
Accuracy and measuring technique for rules
To measure length:
Place the end of the ruler flush with start of material.
Look at exact place on rule where material ends.
Read length on ruler scale.

11. Caring for callipers
Callipers are precision instruments. Protect from damage:
Keep in own protective cases
Never keep loose in a toolbox with other tools
Never drop or knock sharply
Never use excessive force when measuring
Clean metal parts with a slightly oily rag
Clean plastic parts with a dry rag
Inspect jaws for damage
Replace batteries regularly in digital callipers.
Caring for calipers- maintenance.

12. Sliding jaw callipers Have own measuring scales built in
Very accurate - some can measure to 0.01mm (1/100 of a millimetre)
Dial-type callipers
Digital callipers
Types of sliding-jaw calipers.
Vernier callipers

13. Using sliding jaw callipers
Depth gauge measure steps/ heights/ depth of holes.
External jaws measure outside diameters/ thickness/ length.
Versatility of sliding-jaw calipers.
Internal jaws measure gaps/ internal diameters.

14. Using dial-type callipers
Clean jaws and close completely.
Check dial = 0. Adjust if necessary by rotating & locking dial.
Gently close jaws on part being measured. When “feel” is correct, lock slide.
Read number of whole millimetres on left of reference face.
Note dial reading, and add it to whole mm reading.
Description and use of the dial caliper.

15. Using digital callipers
Can make measurements as small as mm (1/1000 millimetre)
Measurements shown directly on digital display
Display can switch between metric and imperial measurements.
Clean & close jaws
Press ON button
Press ZERO button
Check display reads zero, then make measurement.
Description and use of digital calipers.

16. The vernier calliper
Has a special vernier scale marked on the sliding jaw
Measures down to 0.02mm (2/100 millimetre)
Inside jaws
Locking screw
Main scale
Depth gauge
Description and parts of the vernier caliper.
vernier scale
Sliding jaws
Outside jaws

17. Using the vernier calliper
Before measuring, close jaws and check that main scale zero mark lines up exactly with vernier scale zero mark.
Adjust jaws.
You may need to gently “rock” the jaws to get the right feel – not too tight, not too loose.
Lock the slide.
Measuring with the Vernier Caliper- zero check, setting “feel”.

18. Using the vernier calliper cont’d18
Using the vernier calliper cont’d
5. Read number of whole millimetres on main scale, before the vernier zero
6. Look for a vernier scale graduation which lines up exactly with any graduation on the main scale
Read fraction number on vernier scale where the marks line up
Add fraction to whole millimetres to get final measurement. 10 20 30 40 50 60 70 80 2 3 4 5 6 7 8 1 9
0.02 mm
16 whole mm
0.38 mm 10 20 30 40 2 3 4 5 1
0.38 16
Measuring with the Vernier Caliper- continued
Example: whole mm
mm on vernier
= mm

19. Micrometers 1. The outside micrometer
Use to take very accurate measurements
3 types - may look different but all use the same principle.
Outside micrometer
Inside micrometer
Depth micrometer
1. The outside micrometer
Measures width and length
Used for precise measurements eg reconditioning an engine, measuring pistons, valves, crankshafts etc.
Introduction to micrometers; types / application- outside micrometer

20. Micrometers 2. Inside micrometer 3. Depth micrometer
Introduction to micrometers; types / application - inside & depth micrometers
2. Inside micrometer
measures the inside of holes or bores.
3. Depth micrometer
measures the depth of holes/ grooves/ recesses and the height of shoulders.

21. Caring for micrometers
Precision instruments must be treated carefully.
Always:
Clean face of spindle and anvil.
Check zero reading before use.
Avoid dirty or rough components.
Do not adjust micrometers unless trained to do so.
After use - clean, lightly oil, and store in a protective box.
Caring for micrometers; cleaning, checking, storing.

22. The outside micrometer
Measuring range =
The minimum and maximum distance it can measure. It is marked on the frame.
This micrometer can measure:
between millimeters (25mm)
to an accuracy 1/100 of a millimeter (0.01mm ).
Outside micrometer- ranges and measuring resolution

23. Outside micrometer cont.
Can accurately measure the distance between two machined surfaces eg.
- thickness of a shim washer
- diameter of a crankshaft journal.
This micrometers has a range of 50 – 75mm.
Outside micrometer application, ranges, test pieces.
50 mm
Micrometers should have no zero error. They are tested with a special, very accurate test piece.

24. More micrometers Vernier micrometer
has an extra vernier scale on the sleeve
can measure down to 0.001mm (1/1000 of a millimetre).
Vernier and digital micrometers
Digital micrometer
has a display which shows the measurement
may have a conventional scale as well.

25. Using the outside micrometer
Hold micrometer by frame with your left hand.
Open micrometer and clean anvils with a clean cloth.
Check accuracy
Gently close micrometer with ratchet until anvils are touching
or use a test piece.
Look at the scales - they should both read zero.
Using the outside micrometer- checking zero error.

26. Reading the micrometer scale
The sleeve is marked with numbered graduations = whole millimetres.
Sleeve also has half millimetre graduations marked.
Around the thimble - 50 graduations, beginning and ending at 0.

27. Reading the micrometer scale
One full turn of the thimble opens the micrometer by exactly 0.50mm.
A “half mm” graduation is just visible on the datum line.
Two full turns opens the anvils by exactly 1.00 mm.
The 1 mm graduation is just showing on the datum line.
Reading micrometers- relationship of thimble turns to anvil opening.

28. Reading the micrometer scale
Remember – 1 thimble division = 0.01 mm.
To get the final measurement:
Note the number of whole millimetres visible on the datum line.
Add any half millimetres showing on the datum line.
Add the number of thimble graduations lined up with the datum line.
0.01mm

29. Reading the Micrometer Scale
Example 1
4 whole mm showing = 4.00 mm
1 half mm showing = 0.50 mm
5 indicated on the thimble = 0.05 mm
TOTAL = 4.55 mm
Example 2
Reading micrometer- examples.
5 whole mm showing = 5.00 mm
1 half mm showing = 0.50 mm
12 indicated on the thimble = 0.12 mm
TOTAL = 5.62 mm

30. Dial indicator gauge Also called a dial gauge or dial indicator.
Has a face or dial marked in divisions of 0.01 mm (1/100 mm)
Does not take a direct measurement - shows variations from the original zero setting
These variations are transferred from the spindle to the pointer.

31. Dial indicator Used to measure: the bend or run-out in a shaft
the clearance between two parts eg between an engine valve and its guide.
Must be firmly mounted. A magnetic stand or a stand with a screw clamp is often used.

32. Setting up the dial indicator
1. Mount dial gauge firmly on its stand
2. Mount stand securely, to prevent damage from dropping or excessive vibration
3. Keep spindle at right angles (perpendicular) to the surface being checked.

33. Reading the dial indicator
Read the whole millimetres from the inner scale (only for absolute measurements)
2. Read the tenths of millimetres (numbers on outer scale)
3. Read the hundredths of millimetres (small divisions on outer scale).

34. Reading the dial indicator
Example
Step 1
Step 3
Step 1
Read the whole millimetres. The short needle is between the 4 and the 5, so the reading is 4.00 mm.
Step 2
Read the tenths. The long needle is between the 0.20 and the 0.30 mm, so the reading is 0.20 mm.
Step 3
The long needle is 6 small divisions past the 2, so the reading is 0.06 mm.
Step 2

35. Reading the dial indicator
Step 4
To get the final measurement - add up the measurements from Steps 1, 2, & 3.
0.20 mm
4.00 mm
Step mm
Step mm
Step mm
Total = 4.26 mm
0.06 mm

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