How do you read a micrometer to the nearest thousandth of an inch?

How do you read a micrometer to the nearest thousandth of an inch?

• A. Read the sleeve for the inch measurement and the thimble for 0.001 inch increments, then sum the values.
• B. Read the thimble only.
• C. Subtract calibrated marks.
• D. Use a dial indicator.

Answer: (A)

Reading a micrometer to the nearest thousandth involves combining two scales on the instrument: the sleeve shows the inches portion and the thimble shows the thousandths of an inch. First, read the sleeve to capture the whole inches and any fractional inch marked there. Then read the thimble, noting which line lines up with the sleeve reference; this tells you the thousandths to add. Add the sleeve reading and the thimble reading to get the measurement in inches to 0.001 inch. This works because the sleeve provides the base inches and the thimble provides the fine thousandth increments, giving a precise total. Reading only the thimble misses the base inches, subtracting marks isn’t how micrometers are read, and a dial indicator is a different instrument with its own reading method.

Reading a micrometer to the nearest thousandth involves combining two scales on the instrument: the sleeve shows the inches portion and the thimble shows the thousandths of an inch. First, read the sleeve to capture the whole inches and any fractional inch marked there. Then read the thimble, noting which line lines up with the sleeve reference; this tells you the thousandths to add. Add the sleeve reading and the thimble reading to get the measurement in inches to 0.001 inch. This works because the sleeve provides the base inches and the thimble provides the fine thousandth increments, giving a precise total. Reading only the thimble misses the base inches, subtracting marks isn’t how micrometers are read, and a dial indicator is a different instrument with its own reading method.