HOW TO MEASURE WITH A MICROMETER
With a Micrometer you are able to find out the wire diameter of the wire by simply making sure the thimble is at 0 aligned with the 0 on the vernier scale. Then you move the thimble down, with your thumb and place the wire in the measuring surface and roll the thimble up to tighten the spindle on the wire to get your wire diameter.
Micrometers use readings from the sleeve. Each numbered marking is divided into 4 parts, each equaling .025" (25/1000). Therefore, each numbered marking equals .1" (1/10).
For example: (.025 x 4 = .100") (.025 x 8 = .200")
The thimble, which turns, has 25 positions. Each of these markings equals .001" (1/1000). If the sleeve does not fall on an exact .1 section, the dimension will be the lowest complete tenth plus the reading on the thimble.
Example: Sleeve scale mark is between the .2(2/10) and .3(3/10), and the thimble reads 16, or 16 x .001" = .016 (16/1000). Adding the two readings together equals:
Sleeve line = .200+ Thimble line = .016
Total Thickness = .216"