This document specifies the most important design and metrological characteristics of two-point inside micrometers:
—    with a scale interval or digital step of 0,001 mm and 0,01 mm;
—    with analogue or digital indication.
This document is applicable to two-point inside micrometers with and without interchangeable extensions.
This document does not apply to micrometers fitted with a dial gauge, or to jaw micrometers.