Overview
EN ISO 9493:2010 (ISO 9493:2010) is a Geometrical Product Specifications (GPS) standard that specifies the principal design and metrological characteristics of dial test indicators (lever type). It defines how lever-type dial indicators should be constructed, mounted and calibrated so they reliably indicate small linear displacements in dimensional measurement and inspection tasks.
Key topics and requirements
- Scope: Specifies the most important design and metrological characteristics of lever-type dial test indicators.
- Design characteristics:
- General workmanship and orientation requirements to ensure consistent metrological behaviour.
- Three common indicator types: Type S (Standard), Type H (Horizontal) and Type V (Vertical) with guidance on dial-face orientation relative to stylus motion.
- Nomenclature: standard terms for parts (stylus, pointer, bezel, dovetail segments, bias lever, housing, friction/ratchet drive).
- Dial and pointer: scale interval and unit must be labelled; example scale intervals include 0.01 mm, 0.001 mm, 0.002 mm. Pointer rest position guidance (e.g., minimum counterclockwise rest).
- Dovetail mounting and clamping stems: recommends dovetail segments for attachment; clamping stems should conform to fit tolerance h6, common diameters 4 mm, 6 mm, 8 mm, with a controlled length no shorter than 12 mm.
- Metrological characteristics:
- Framework for declaring and verifying maximum permissible error (MPE) and maximum permissible limit (MPL) for relevant characteristics.
- Requirements covering stylus characteristics, measuring forces, and bidirectional measurement capability.
- Conformance and calibration:
- Procedures for proving conformance with the specification and references to calibration/uncertainty guidance.
- Informative annexes provide example error diagrams, sample data sheets, calibration notes and practical use guidance.
Applications and users
- Manufacturers of lever-type dial test indicators and accessory suppliers (dovetail clamps, stands).
- Calibration laboratories and metrology laboratories that certify dial indicators.
- Quality control engineers, inspection technicians and machine shops using dial indicators for part set-up, runout checks and small-displacement measurement.
- Standards bodies and product designers ensuring instrument interchangeability and traceable measurement.
Related standards and references
- ISO 14978 (GPS measuring equipment concepts)
- ISO 14253 series (inspection decision rules and uncertainty guidance)
- ISO/IEC Guide 98-3 (GUM: uncertainty of measurement)
- ISO/IEC Guide 99 (VIM: metrology vocabulary)
EN ISO 9493:2010 is essential when selecting, specifying or calibrating lever-type dial indicators to ensure repeatable, traceable dimensional measurement in industrial and laboratory environments.
