This standard specifies the terms and definitions, types and basic parameters, requirements, inspection methods, signs and packaging of torsion spring comparators. This standard is applicable to the division values of 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 2 μm, 5 μm, 10 μm, and the indication range is ±30 scale division, ±60 scale division, ±100 scale division, clamping sleeve A torsion spring comparator with a barrel diameter of 28 mm.