Overview
EN ISO 25178-70:2014 - "Geometrical product specification (GPS) - Surface texture: Areal - Part 70: Material measures" specifies the characteristics and classifications of material measures used for the periodic verification and adjustment of areal surface texture measurement instruments. As part of the ISO 25178 areal surface texture family, this standard defines what physical artefacts and certification information are required to support reliable, traceable areal surface texture measurements.
Key Topics and Requirements
- Scope and purpose: Establishes the characteristics of material measures intended for use in periodic verification and adjustment of areal instruments (e.g., coherence scanning interferometers, confocal microscopes, focus variation systems).
- Requirements for material measures: General rules on construction, stability and documentation (including the material measure certificate) needed to support instrument verification.
- Types of material measures: Comprehensive classification covering both profile and areal artefacts. Examples from the standard include:
- Profile types (e.g., periodic sinusoidal, triangular, rectangular, prism, irregular profile)
- Areal types (e.g., perpendicular grooves, circular grooves, hemisphere, cross grating, radial sinusoidal, flat plane, photochromic patterns)
- Measurement and evaluation guidance: Annexes provide normative and informative material on measurement requirements, an equivalence table for material names, evaluation of spacing measurands on areal instruments, and the relationship to the GPS matrix model.
- Normative references: The standard links to ISO 25178-2 (terms/parameters), ISO 3274, ISO 25178-601, ISO 10012 and ISO/IEC 17025 for laboratory competence and measurement-management practices.
Applications
- Calibration and periodic verification of areal surface texture instruments to ensure measurement accuracy and repeatability.
- Adjustment and validation of instrument performance after maintenance or software updates.
- Quality control in manufacturing sectors where surface texture affects function (e.g., automotive, aerospace, medical implants, precision machining).
- Inter-laboratory comparisons and traceability, where certified material measures support conformity to GPS and metrological best practice.
Who should use this standard
- Metrology and calibration laboratories
- Instrument manufacturers and service providers
- Quality engineers and process engineers concerned with surface functional performance
- R&D teams developing or validating areal surface measurement methods
Related standards
- ISO 25178 series (Parts 1, 2, 3, 6, 70, 71, 601–606, 701)
- ISO 3274, ISO 10012, ISO/IEC 17025, ISO/IEC Guide 99
Keywords: EN ISO 25178-70:2014, areal surface texture, material measures, surface texture measurement instruments, verification and adjustment, GPS.
