ISO 25178-71:2026

Geometrical product specifications (GPS) — Surface texture: Areal — Part 71: SDF file format ISO 25178-71:2026

Publication date:   Aug 26, 2026

Scope

This document specifies Type S1 software measurement standards, reference data, and Type S2 software measurement standards, reference software, for verifying the software of measuring instruments. It also specifies the surface data file (SDF) format of Type S1 software measurement standards for the calibration of instruments for the measurement of surface texture by the profile and areal method as defined in the profile and areal surface texture chain of standards, the chain links F and G.
The SDF format applies to profile and areal topography measurement data extracted with an orthogonal grid (see ISO 14406:2010, 5.2) and equidistant sampling intervals, regardless of the measurement principle.
NOTE            Throughout this document, the terms “reference data” and “reference software” are used as substitutes for software measurement standards of Type S1 and Type S2, respectively. In practice, “reference data” is sometimes referred to as “software gauge” or “softgauge”.