digital micrometer

1. Become familiar with the anatomy of a micrometer. The following numbers correspond to the diagram in the introduction.
   
   
   1. Ratchet stop
   2. Thimble
   3. Thimble scale
   4. Stock
   5. Thimble lock
   6. Spindle
   7. Anvil
   8. Body

2. 

   

   Place the object between the anvil and spindle.

3. 

   

   Spin the ratchet stop until the spindle meets object.
4. Spin ratchet stop until you hear 3 clicks.

5. 

   

   Verify both the anvil and spindle are touching the object evenly.

6. 

   

   Set the thimble lock while the micrometer is still on the object.

7. 

   

   Remove the micrometer from the object once it's been locked.

Reading (Inch-System)

1. Note that the measurement will start with the whole number 2.___”

2. 

   

   Look at the 100 thousandths markings in the stock (2.5).
3. Look at individual 25 thousandths markings exposed next to the 100 thousandths, i.e. after the 5 (.25).
4. Find the number and corresponding marking on the thimble scale closest to but underneath the measurement line on the stock (20).
5. Add that number to the 25 thousandths marking (20 + 25), measurement should read so far 2.545.
6. Flip the micrometer over to read to the 10 thousandths marking.

7. 

   

   Locate the marking on the stock that is inline with the marking on the thimble (4), final measurement should now read 2.5454.

• Practice -- you will develop a "touch" or "feel" for it.
• Measure the desired object multiple times as a check on your work.
• Remember also that an outside micrometer, when used correctly, is much more accurate than calipers.