The length, quantitatively and objectively, identifies a material body according to a single main or prevalent dimension of the body itself. The measure of length leads to the knowledge of the geometry of bodies, that is to their “dimensions.” Many length measurements are also based on many (indirect) measurements of other physical quantities.
Length measurements can be obtained with different instruments; they are:
- Graduated ruler;
- Palmer micrometer;
- Electrical comparators for length measurements;
- Pneumatic dial gauge for length measurement;
- Meter (or metre) unit of length