Which tool would you use to measure the internal diameter of a pipe?

The tool selected, an inside micrometer, is specifically designed for measuring the internal diameters of pipes and tubes with high accuracy. Inside micrometers have a set of measuring tips that expand to take measurements from within a hollow object, allowing for precise readings of the diameter. This capability makes it particularly useful in contexts where precision is critical, such as in aviation maintenance where components must meet stringent specifications.

Calipers, while versatile and capable of measuring both external and internal dimensions, can sometimes be less precise than micrometers when it comes to ensuring accurate internal diameter measurements due to their design. A screw gauge can also measure small internal dimensions but typically is not the first choice for cylindrical measurements like those of pipes. A multimeter, on the other hand, is used for measuring electrical values and has no application in measuring physical dimensions like diameter. Therefore, the inside micrometer is the most suitable tool for measuring the internal diameter of a pipe effectively.