Which micrometer type is used to measure internal dimensions?

Which micrometer type is used to measure internal dimensions?

• A. Inside micrometer
• B. Outside micrometer
• C. Depth micrometer
• D. Vernier micrometer

Answer: (A)

Measuring internal dimensions requires a tool that can reach inside a hole or bore and sense the distance between its inner surfaces. An inside micrometer is built for that purpose: its measuring heads fit into the bore and are advanced by the micrometer screw until the anvils touch the bore walls, giving the internal diameter on the scale. Outside micrometers are intended for external dimensions, not inside a hole. A depth micrometer measures how deep a feature is from the surface, not the cross-sectional diameter. A Vernier micrometer is simply a micrometer with a vernier scale for finer external measurements, not suited for internal bore measurements. So the inside micrometer is the tool designed for measuring internal dimensions.

Measuring internal dimensions requires a tool that can reach inside a hole or bore and sense the distance between its inner surfaces. An inside micrometer is built for that purpose: its measuring heads fit into the bore and are advanced by the micrometer screw until the anvils touch the bore walls, giving the internal diameter on the scale. Outside micrometers are intended for external dimensions, not inside a hole. A depth micrometer measures how deep a feature is from the surface, not the cross-sectional diameter. A Vernier micrometer is simply a micrometer with a vernier scale for finer external measurements, not suited for internal bore measurements. So the inside micrometer is the tool designed for measuring internal dimensions.