Overview
EN ISO 16610-31:2025 (ISO 16610-31:2025) is the CEN-adopted second edition standard for Geometrical Product Specifications (GPS) - Filtration, Part 31: Robust profile filters: Gaussian regression filters. The document specifies how to apply robust Gaussian regression filters to surface profiles to separate large-scale and small-scale lateral components, particularly reducing the influence of protruding dales and hills. The standard covers both open and closed profiles (including roundness filtering) and provides continuous filter definitions and a normative iterative solution for implementation.
Key Topics
- Purpose: Define robust Gaussian regression filters for reliable surface profile filtration and reconstruction without altering the original profile.
- Filter types: Continuous robust Gaussian regression filters for open and closed profiles; concepts extendable to generalized closed profiles and re-entrant features.
- Filter behavior: Transmission characteristics and how filters separate large-scale (form) and small-scale (texture) lateral components.
- Mathematical framework: Filter equations, regression degree (p), nesting index series and designation rules (standard defines how to specify a filter unambiguously).
- Implementation: Normative iterative solution for continuous Gaussian regression filters and guidance on iterative computation.
- Support material: Informative annexes with examples, relationships to filtration and GPS matrix models, and links to related parts of the ISO 16610 series.
Applications
EN ISO 16610-31:2025 is targeted at professionals needing robust, repeatable profile filtration in surface metrology. Typical applications include:
- Surface texture and roughness analysis in quality control and R&D.
- Roundness and closed-profile filtration for bearings, shafts and precision components.
- Manufacturing process validation (machining, grinding, additive manufacturing) where protruding features can bias texture metrics.
- Metrology software and CMM developers implementing GPS-compliant filtration algorithms.
- Standards-driven verification in automotive, aerospace, medical devices and tooling industries.
Users benefit from more stable texture parameters when profiles contain outliers (protruding hills/dales) and from standardized filter designation for consistent measurement reporting.
Related Standards
- ISO 16610-1 - Filtration: Overview and basic concepts
- ISO 16610-20 / 21 / 22 - Linear profile filters (basic concepts, Gaussian, spline)
- ISO 16610-30 - Robust profile filters: Basic concepts
- ISO 14638, ISO 8015, ISO 14253-1 - GPS matrix, fundamental rules, decision rules
- ISO/IEC Guide 99 (VIM) - Metrology vocabulary
Keywords: EN ISO 16610-31:2025, ISO 16610-31, robust Gaussian regression filters, GPS filtration, profile filtering, surface profiles, roundness filtering, nesting index, regression degree.