Which option represents the vernier scale graduation of a micrometer?

Which option represents the vernier scale graduation of a micrometer?

• A. Surface gauge
• B. Dial indicator
• C. Machinist scale
• D. 1/10000 in (0.0001 in)

Answer: (C)

The micrometer reads by combining two scales: a fixed main scale (the sleeve) and a rotating thimble that carries the vernier. The main scale, often called the machinist scale, provides the baseline measurement, while the vernier on the thimble offers the finer subdivision. The vernier graduations align with the markings of the machinist scale to interpolate between them, giving the precise reading. That relationship is why the term for the scale involved in the vernier readout is the machinist scale. The other options refer to different instruments or specify a resolution, not the scale used to read the vernier.

The micrometer reads by combining two scales: a fixed main scale (the sleeve) and a rotating thimble that carries the vernier. The main scale, often called the machinist scale, provides the baseline measurement, while the vernier on the thimble offers the finer subdivision. The vernier graduations align with the markings of the machinist scale to interpolate between them, giving the precise reading. That relationship is why the term for the scale involved in the vernier readout is the machinist scale. The other options refer to different instruments or specify a resolution, not the scale used to read the vernier.