1. Measurement

2. Micrometer Digital Micrometer
The micrometer is used for where accurate measurement (to 1000th of a mm) is required.
Micrometer

3. Micrometer Parts Anvil Glass hard and optically flat
Spindle Moves ½ mm for every full rotation of the Sleeve
Spindle Lock Locks spindle in place
Barrel & Sleeve Used to obtain measurements
Ratchet Prevents over tightening (and thus damaging) micrometer

4. Reading a Micrometer
When reading a Micrometer it is important to remember that one turn of the spindle represents ½ mm.

5. Vernier Calipers
Named after its inventor the Vernier scale is incorporated in many measuring instruments, the most commonly used of which is the sliding calliper gauge as shown above. These gauges can be used for both internal and external measurement.

6. Using Vernier Calipers
External Measurement
Vernier Calipers can be used to measure both internal and external dimensions
Internal Measurement

7. Reading Vernier Calipers
Imperial Scale
Metric Scale
In the illustration above you first read this scale
This reads 2.4cm
Then you look along the this scale and find where two lines line up
This adds a further 0.062mm
Add these two figures together to give = 2.462cm

8. Depth Gauge
As shown in the diagram on the left the Depth Gauge can be used to measure the depth of holes

9. Calipers Internal Calipers External Calipers
Calipers can be used to gauge the size of an object. As Calipers have no in built scale all dimensions must be set with a rule (as shown). This makes Calipers less accurate than both the Micrometer and Vernier Calipers
Setting Calipers

10. The End