Overview
ISO 5436-2:2012 - "Geometrical product specifications (GPS) - Surface texture: Profile method; Measurement standards - Part 2: Software measurement standards" specifies software-based measurement standards for verifying surface texture measurement software. The standard defines two types of software etalons: Type F1 (softgauge / reference data files) and Type F2 (reference software), the file format for Type F1 (.smd) and the required metadata for traceable calibration of profile-method surface texture instruments (as defined in ISO 3274).
Keywords: ISO 5436-2, surface texture, profile method, software measurement standards, softgauge, .smd, metrology, GPS.
Key Topics
- Type F1 - Reference data (softgauge):
- Computer data files (.smd) that represent a digital primary profile for software verification.
- File uses 7-bit ASCII, divided into four records, terminated by ASCII 3 and ASCII 26.
- Header (Record 1) includes revision string, file identifier, feature type (PRF/SUR), axis info (CX/CY/CZ, PR/PA), number of points, units, scale factor and data type (I/L/F/D), and incremental spacing.
- Record 2 is optional metadata (DATE, INSTRUMENT_ID, PROBING_SYSTEM, COMMENT, etc.).
- Record 3 contains the raw data; Record 4 provides a checksum.
- Type F2 - Reference software:
- Traceable software used to compute certified results from common input data; used to compare/calibrate instrument software.
- Type F2 can be used to certify Type F1 reference data.
- Traceability and uncertainty: Reference software values and reference data must be traceable and suitable for producing known uncertainties in measurands.
- Scope of verification: Designed to verify filter algorithms, parameter calculations, form removal, decimation, stylus corrections and other processing steps up to the primary profile.
Applications
- Calibration and verification of surface texture measurement systems (stylus and other profile-type instruments).
- Quality and metrology labs ensuring software implementations conform to GPS methods.
- Instrument manufacturers and software developers validating filtering, parameter calculations, and file I/O.
- Research and services that require certified reference data (.smd softgauges) for inter-laboratory comparisons or software certification.
Related Standards
- ISO 3274 (profile instruments - nominal characteristics)
- ISO 5436-1 (material measures for surface texture)
- ISO 16610-21 (linear profile filters - Gaussian)
- ISO 17450-2, ISO/IEC Guides on uncertainty and metrology vocabulary
Practical tip: use Type F1 .smd softgauges together with Type F2 reference software to separately validate data handling and algorithmic processing in your surface texture measurement workflow.