ISO 12781-1-2011 pdf download.Geometrical product specifications (GPS)一Flatness一 Part 1: Vocabulary and parameters of flatness.
This part of ISO 12781 defines the temis and concepts related to flatness of individual complete integral features only.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 14660-1:1999, Geometrical Product Specifications (GPS) — Geometrical features — Part 1: General terms and definitions
ISO 14660-2:1999, 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
ISO 17450-1:— 1), Geometrical Product Specifications (GPS) — General concepts — Part 1: Model for geometrical specification and verification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 14660-1, ISO 14660-2, ISO 17450-1 and the following apply.
3.1 General terms
3.1.1 flatness
property ofa plane
3.1.2 nominal plane
mathematically defined plane as specified by the design
3.2 Terms relating to the surface
3.2.1 extracted surface
(flatness> digital representation of the real surface See Figure 1.
NOTE The extraction conventions for flatness are given in ISO 12781-2. This extracted surface is an extracted integral feature as defined in ISo 14660-1.
3.2.2 flatness surface
extracted surface (type plane) intentionally modified by a filter
NOTE 1 This is the surface to which the concepts and parameters of this part of ISO 12781 can be applied.
NOTE2 The areal Gaussian fiter is a convolution of two orthogonal profile Gaussian fiters.
3.2.3 local flatness deviation
deviation of a point on a flatness surface from a reference plane, the deviation being normal to the reference plane See Figure 2.
NOTE 1 The deviation is negative if from the reference plane the point lies in the direction of the material.
NOTE 2 For reference plane, see 3.3.1.ISO 12781-1 pdf download.