Overview
EN ISO 13385-1:2019 (also published as ISO 13385-1:2019) is a Geometrical Product Specification (GPS) standard that defines the principal design and metrological characteristics of callipers - both analogue (vernier or circular/dial scale) and digital (electronic display). Issued in 2019 and adopted by CEN as EN ISO 13385-1:2019, this second edition replaces the 2011 version and positions callipers within the GPS framework for dimensional measuring equipment.
Key topics and requirements
The standard focuses on practical, testable characteristics rather than process prescriptions. Major technical topics include:
- Design characteristics: nomenclature, essential dimensions and functional elements of callipers (slider, beam, jaws, depth/step features).
- Metrological characteristics: rated operating conditions, reference point definitions and the parameters that influence measurement accuracy.
- Errors and test methods: definitions and test procedures for common error types such as partial surface contact error (E) and shift error (S) (including internal, crossed knife-edge, depth/step cases).
- Maximum permissible errors (MPE): default MPE values are provided (see Annex B) and methods for verifying conformity against these limits.
- Conformity and uncertainty: guidance on measurement uncertainty, decision rules for acceptance/rejection, and conformity determination in line with GPS rules.
- Marking and documentation: requirements for instrument identification and information needed for traceable use.
- Annexes: informative calibration guidelines (Annex A), normative default MPE values (Annex B), and the relationship to the GPS matrix model (Annex C).
Applications and users
EN ISO 13385-1:2019 is intended for organizations and professionals who design, manufacture, use or verify callipers:
- Quality and inspection teams in manufacturing (metalworking, automotive, aerospace)
- Calibration and metrology laboratories that certify handheld measuring instruments
- Instrument manufacturers developing or specifying caliper products (analogue or digital)
- Procurement specialists specifying measuring equipment in technical specifications
- Standards bodies and conformity assessment bodies applying GPS decision rules
Use this standard to ensure calipers meet defined functional and metrological expectations, to support calibration programs, and to harmonize acceptance criteria across suppliers and inspection labs.
Related standards
This part of the GPS family references and aligns with:
- ISO 14978 (GPS measuring equipment concepts)
- ISO 14253-1 / -5 / TR 14253-6 (decision rules, uncertainty, verification)
- ISO/IEC Guide 98-3 (GUM: uncertainty of measurement)
- ISO/IEC Guide 99 (VIM: metrology vocabulary)
Keywords: EN ISO 13385-1, ISO 13385-1:2019, callipers standard, calipers design, metrological characteristics, GPS, dimensional measuring equipment, MPE, calibration guidelines.
