Overview
ISO 16610-1:2015 - "Geometrical product specifications (GPS) - Filtration - Part 1: Overview and basic concepts" - defines the foundational terminology and framework for GPS filtration. It is a general GPS standard that establishes how filtration is described, indexed and referenced across the ISO 16610 series. The document generalizes the concept of filtration and provides the building blocks used to create, combine and specify profile and areal filters used in surface texture and form analysis.
Key topics and technical concepts
- Scope and purpose: Defines basic terminology for GPS filtration and the framework for fundamental procedures used in filtration.
- Primary mathematical model: A hierarchical set of mathematical models (each described by a finite number of parameters) used to represent a surface portion. Examples include truncated Fourier series and other limited representations.
- Nesting index: A numerical index that identifies the level of the nested model (e.g., cut-off wavelength for linear filters, disc radius for morphological filters). Nesting indices separate long- and short-wavelength surface components.
- Primary surface / primary profile: The representation of a surface portion when expressed by a specified primary mathematical model and nesting index.
- Primary mapping and criteria: Definitions of mappings indexed by nesting index, with the sieve and projection criteria ensuring consistent behavior when mappings are composed or reapplied.
- Filter types and operators: Differentiates profile filters and areal filters, and introduces the concept of constructing filters from primary mappings (e.g., weighted sums, suprema).
- Robustness and outliers: Terminology for filter sensitivity to input phenomena such as scratches or steps; identifies outliers and discusses limits of detection.
- Filter equation: The mathematical description of a filter (note: filter equations describe behavior but do not prescribe numerical algorithms).
- Supporting material: Informative annexes provide illustrative examples, a masterplan for the ISO 16610 series, pros/cons of filter types, concept diagrams and relationships to the GPS matrix model.
Practical applications and users
ISO 16610-1 is intended for professionals involved in surface specification, measurement and verification:
- Metrologists and quality engineers defining surface texture specifications
- Design and manufacturing engineers specifying functional surface requirements
- Software developers of measurement and filtering tools (CMM, surface profilometers, areal instruments)
- Test labs and certification bodies implementing GPS filtration procedures
Typical applications include surface texture filtering for functional assessment, separating form/waviness/roughness components, handling end effects and outliers, and selecting appropriate filters (Gaussian, spline, morphological, robust) for verification.
Related standards (selection)
- ISO 16610 series (detailed filter parts: Gaussian, spline, morphological, robust, areal/profile filters)
- ISO 17450-1 / ISO 17450-2 (GPS general concepts and tenets)
- ISO/IEC Guide 99 (VIM - metrology vocabulary)
- ISO 8015 and ISO 14253-1 (GPS decision rules and verification principles)
Keywords: ISO 16610-1, GPS filtration, geometrical product specifications, nesting index, cut-off wavelength, profile filter, areal filter, primary mathematical model, surface texture filtering.