🔍 Key Concepts
• How to read a vernier micrometer: add the sleeve (barrel) reading, the thimble reading, and then the vernier reading for ten‑thousandths of an inch.
• On most inch micrometers the sleeve scale shows 0.025 inch per line, the thimble scale shows 0.001 inch per division, and the vernier scale refines this to 0.0001 inch.
• On figure "F", note which thimble graduation lines up exactly with a line on the vernier scale – that tells you the final 0.0001-inch digit.
💭 Think About
• First, from the sleeve (horizontal lower scale), decide what the base reading is: what is the last full 0.025-inch mark that is completely to the left of the thimble edge? Convert that to a decimal inch value.
• Next, on the thimble (right‑hand vertical scale), find which thousandths mark (0–24) is exactly in line with the reference line on the sleeve; add that 0.001-inch value to your base reading.
• Finally, look at the vernier (the small numbered scale opposite the thimble marks). Which vernier line aligns perfectly with a thimble division? That vernier number, multiplied by 0.0001 inch, gives the last digit – compare that full value with the four answer choices.
✅ Before You Answer
• Be sure you are reading only the last fully visible sleeve division to the left of the thimble, not the one partly covered.
• Verify which thimble mark is exactly on the sleeve’s reference line; if it’s between marks, do not use it.
• Confirm that the vernier line you choose is the single best alignment with a thimble line; very small misalignments can change the ten‑thousandths digit and eliminate one or more choices.