Overview
ISO 9493:2010 - "Geometrical product specifications (GPS) - Dimensional measuring equipment: Dial test indicators (lever type) - Design and metrological characteristics" defines the essential design and metrological requirements for lever‑type dial test indicators. It specifies how these instruments should be built, marked and characterized so they can be reliably used for dimensional inspection within a GPS framework.
Key topics
- Instrument types and nomenclature
- Three common types: Type S (Standard), Type H (Horizontal) and Type V (Vertical), with defined dial orientations.
- Standardized names for features (bezel, dial, pointer, stylus, dovetail, bias lever).
- Design characteristics
- Interchangeable spherical stylus tips made from hard wear‑resistant materials.
- Dovetail mounting and clamping stem requirements (common nominal diameters: 4, 6, 8 mm) with fit tolerance h6 and a minimum controlled stem length of 12 mm.
- Stylus adjustment range from −90° to +90° relative to the indicator axis.
- Dial layout rules: minimum pre‑span/post‑span (pointer travel) and at least one full revolution of measuring range; provision for revolution counting if range exceeds one revolution.
- Zero adjustment via bezel with adequate friction to hold setting.
- Metrological characteristics
- Manufacturers must declare Maximum Permissible Error (MPE) and Maximum Permissible Limit (MPL) for key characteristics including hysteresis, repeatability and error of indication over specified ranges.
- Measuring forces (maximum and minimum) and stylus metrological suitability must be specified.
- Conformance and documentation
- Requirements for proving conformance, calibration references, marking and manufacturer data sheets.
- Informative annexes include example error diagrams, data‑sheet templates, calibration guidance, user notes and relation to the GPS matrix.
Applications and users
ISO 9493:2010 is practical for:
- Metrology and calibration laboratories establishing test/calibration procedures and uncertainty budgets.
- Manufacturers of dial test indicators to design products that meet GPS requirements and to prepare compliant datasheets.
- Quality engineers, inspection teams and machine shops selecting, using and checking dial test indicators for dimensional inspection tasks.
- Procurement and compliance officers who need standardized acceptance criteria for instruments.
Typical applications include part inspection, run‑out checks, fixture setup and machine tool verification where lever‑type dial indicators are used for short‑range displacement measurements.
Related standards
- ISO 14978 (GPS measuring equipment general concepts)
- ISO 14253‑1 (Decision rules for proving conformity)
- ISO/IEC Guide 98‑3 (GUM - uncertainty of measurement)
- ISO/IEC Guide 99 (VIM - metrology vocabulary)
Keywords: ISO 9493:2010, dial test indicators, lever type, geometrical product specifications, GPS, metrological characteristics, MPE, dovetail mounting, stylus.
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