Which device is most suitable for measuring small internal dimensions?

The micrometer is particularly well-suited for measuring small internal dimensions because it offers high precision and accuracy. It is designed to measure small distances with a high degree of resolution, typically down to 0.01 mm or better, depending on the type of micrometer used. This capability makes it ideal for applications requiring precise measurements of small objects or internal features, such as the inner diameters of small tubes or the thickness of thin materials.

Micrometers operate using a screw mechanism, which amplifies small movements, allowing for very fine measurements. The scale on a micrometer can usually be read to a finer resolution than other measuring tools, providing an advantage in applications where minute differences matter.

While calipers can also measure internal dimensions and may be easier to handle in some cases, they do not offer the same level of precision as a micrometer. Borescopes are typically used for visual inspections inside hollow objects and may not provide precise measurements, while a ruler is generally not suitable for small internal measurements due to its larger scale and lower precision.