Check the zero error before measuring
Place the object between the anvil and spindle
Turn the thimble until the spindle just touches the object
Read the sleeve or main scale first
Note the last visible whole millimetre and half-millimetre mark
Read the thimble scale next
Count the division that lines up with the sleeve reference line
Multiply the thimble reading by the micrometre’s least count
Add the sleeve reading and thimble reading
Apply zero correction if needed
Record the final measurement in millimetres or micrometres