A Micrometer is a precision measuring instrument. Also called a "Mike" by Pundits.
There are many different styles and sizes of micrometers. This information will pertain to the common micrometer caliper.
It consists of only a few parts. The Frame, Anvil, Spindle, Cam Lock, Hub, Thimble, and Ratchet Cap.
The measurement is taken by placing the item you want to measure between the Anvil and Spindle. Tighten the Ratchet Cap with the thumb and index finger until it slips. Then lock the Cam Lock and slide the micrometer off.
With the micrometer off you can now take the readings.
The first reading would be the tenths and hundredths on the Hub.
Figure 1 reads .475. Pronounced: Four hundred seventy five thousandths of an inch. A Second reading is taken from the Thimble.
Figure 1 reads almost .019, so we use .018. Pronounced: Eighteen thousandths of an inch. Next add the Hub reading to the Thimble reading. (.475 + .018= .493)
Pronounced: Four hundred ninety three thousandths of an inch.
For accuracy of ten-thousandths of an inch (.0001) take the reading from the Vernier scale on the Hub (Figure 2). Look for the Thimble graduation that lines up with the Vernier scale. Add that Number to the previous reading of .493. (.493 + .0009= .4939)
Pronounced: Four thousand nine hundred thirty nine ten-thousandths of an inch.
.1 = one tenth
.10 = ten hundredths
.01 = one hundredth
.010 = ten thousandths
.001 = one thousandth
.0010 = ten ten-thousandths
.0001 = one ten-thousandth
.0100 = one hundred ten-thousandths (of an inch)
Cleaning: Wipe with a clean rag and always keep it well oiled. This well prevent rust and premature wear.
Calibrating: Calibrating is usually performed by measuring a Calibrated block. Then the hub is usually turned with a spanner wrench to match the blocks dimensions. (See your specific manufacturers instructions)
It's that simple!