Overview
EN ISO 13385-2:2020 - "Geometrical product specifications (GPS) - Dimensional measuring equipment - Part 2: Design and metrological characteristics of calliper depth gauges" defines the essential design and metrological requirements for calliper depth gauges with either analogue indication (vernier or dial) or digital display. Adopted by CEN as EN ISO 13385-2:2020, this GPS standard updates and supersedes the 2011 edition and forms part of the ISO GPS matrix for size and distance measurement.
Key topics and requirements
- Scope and definitions: Clear terminology for calliper depth gauges, measuring face contact (full vs partial), and related concepts aligned with ISO 14978 and VIM.
- Design characteristics: Guidance on general design, nomenclature and dimensional features of the beam, slider and measuring faces; reference to ISO 14978 for common design rules.
- Metrological characteristics:
- Rated operating conditions and the instrument’s reference point.
- Test methods for verifying performance under specified conditions.
- Specific error types described, such as partial surface contact error (E) and shift error (S), with limits (MPE) and handling of special cases.
- Provision of default Maximum Permissible Errors (MPE) in Annex B.
- Conformity assessment:
- Rules for determination of conformity, measurement uncertainty considerations (per GUM/ISO Guide 98-3) and decision rules referenced to ISO 14253-1 and ISO 14253-5.
- Marking and documentation: Requirements for labelling and information to accompany the instrument.
- Annexes:
- Annex A: informative calibration guidelines;
- Annex B: normative default MPE values;
- Annex C: relation to the GPS matrix model.
Applications and who uses it
This standard is practical for organizations and professionals involved in precision measurement and quality control:
- Manufacturers of calliper depth gauges (design & production).
- Calibration laboratories and metrology labs performing verification and calibration.
- Quality engineers, inspection teams and metrologists implementing GPS-compliant measurement systems.
- Procurement and compliance teams specifying acceptable instruments and MPE for production or inspection.
Typical applications include inspection of steps, bores, recess depths and features where accurate depth measurement is required in manufacturing, inspection, and calibration environments.
Related standards (key references)
- ISO 14978 - General concepts and requirements for GPS measuring equipment
- ISO 14253-1 / ISO 14253-5 / ISO/TR 14253-6 - Decision rules and uncertainty in verification testing
- ISO/IEC Guide 98-3 (GUM) - Uncertainty of measurement
- ISO/IEC Guide 99 (VIM) - Metrology vocabulary
Keywords: EN ISO 13385-2:2020, calliper depth gauges, GPS, dimensional measuring equipment, metrological characteristics, MPE, calibration, ISO 14978, ISO 14253.
