Overview
EN ISO 17450-2:2012 - Geometrical product specifications (GPS) Part 2 - defines the fundamental vocabulary and conceptual framework used across GPS standards. Published by CEN as the European adoption of ISO 17450-2:2012, this part focuses on the basic tenets, formal specifications, operators, sources of uncertainty, and potential ambiguities that affect geometry specification and verification in engineering and metrology.
Key topics
- Terms and definitions: Clear definitions for specification operations, specification operators, verification operations, and uncertainty-related concepts used consistently across GPS standards.
- Specification operations: Distinction between default, special, and actual specification operations - how mathematical/algorithmic expressions and modifiers define geometrical requirements (e.g., filtration, envelope requirements).
- Verification operations: How measurement methods and apparatus implement specification operations, including the concept of a perfect verification operation and practical deviations.
- Uncertainty and impact: Discussion of measurement and method uncertainties and how they influence GPS basic tenets and decision rules (e.g., ambiguity of function description and specification).
- Processes: Defined specification and verification processes to ensure consistent interpretation of technical product documentation.
- Informative annexes: Concept diagram, drawing indications, and relationship to the broader GPS matrix model that place this part in the GPS standard family.
Practical applications
- Provides a common language and framework for producing unambiguous engineering drawings, CAD specifications, and inspection plans.
- Guides metrology and quality engineers in selecting and documenting specification operations and corresponding verification methods.
- Helps inspection laboratories and calibration facilities understand how measurement uncertainty affects conformity assessment and decision rules.
- Supports design, manufacturing, and quality teams in reducing specification ambiguities that can cause rework, nonconformances, or litigation.
Who should use this standard
- Metrology and calibration engineers
- Quality assurance and inspection personnel
- Design and CAD/CAM engineers who prepare technical product documentation
- Manufacturing engineers responsible for tolerancing and process capability
- Standards developers and testing laboratories working with GPS systems
Related standards
EN ISO 17450-1:2011 (GPS - Part 1: Model for geometrical specification and verification) and normative references that inform uncertainty and terminology, including:
- ISO 14253-2 (uncertainty guidance for GPS measurement)
- ISO 14660-1 (geometrical feature terms)
- ISO 14978 (requirements for GPS measuring equipment)
- ISO/IEC Guide 98-3 (GUM) and Guide 99 (VIM)
EN ISO 17450-2:2012 is essential for consistent, unambiguous application of GPS principles across design, inspection, and verification workflows.
