This standard specifies the method to assess departure from roundness through measurement by two- and three-point methods.
This standard is applicable to the measurement of the departure from roundness of circular elements inside and outside parts.
This standard is a kind of specific provision on the detection of departure from roundness as stated in GB/T 1958.
Note: because the value obtained from two- and three-point measurement is different from the actual value of departure from roundness, it shall be corrected according to the correction factor given in this standard.
2 Normative References
The following standards contain provisions which, through reference in this standard, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding corrections to), or revisions of, any of these publications do not apply. However, the parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards. For undated references, the latest edition of the normative document referred to applies.
GB/T 1182 Geometrical Tolerancing - Generalities, Definitions, Synbiks, Indications on Drawings(GB/T 1182-1996, eqv ISO 1101: 1996)
GB/T 1958 Rules for Inspection of Form and Position Tolerances
GB/T 18780.1 Geometrical Product Specification (GPS) - Geometrical Features - Part 1: General Terms and Definitions (GB/T 18780.1-2002, idt ISO 14660-1: 1999)
GB/T 18780.2 Geometrical Product Specifications(GPS) - Geometrical Features - Part 2: Extracted Median Line of a Cylinder and a Cone, Extracted Median Surface, Local Size of an Extracted Feature(GB/T 18780.3-2002, ISO 14660-2: 1999, IDT)
