SIST EN ISO 16610-62:2023 PDF

Overview

EN ISO 16610-62:2023 - "Geometrical product specifications (GPS) - Filtration - Part 62: Linear areal filters: Spline filters" - defines the characteristics and behaviour of linear areal spline filters used in surface metrology. The standard specifies a low-pass areal filter based on cubic splines that preserves global shape (global shape retainment) while separating long-wave (form/waviness) and short-wave (roughness) components on surface topography maps.

Key topics and technical requirements

• Filter type and scope
  • Defines the linear areal spline filter as the areal extension of the linear profile spline filter (ISO 16610-22).
  • Covers both linear planar filters (open surfaces) and linear cylindrical filters (surfaces with periodic continuation).
• Mathematical formulation
  • Presents a low-pass filter formula for cubic spline filters on uniformly sampled grids, using transformation matrices (Ax, Ay) applied to the input height map.
  • Specifies matrices for discretized differentiation (P, Q) and the unity matrix E used in the filter matrices.
• Key parameters
  • Regularization parameter (α, μ) - relates spline smoothness to the cut-off wavelength (λc); determines degree of smoothing.
  • Tension parameter (β) - influences the slope of the transfer function (transmission characteristics).
  • Guidance for computing αx, αy for lateral axes and modifications for distorted sampling grids.
• Transmission characteristics and filter designation
  • Defines the cut-off wavelength convention (50% amplitude transmission) and identifies how the spline filter is designated (filter type plus cut-off).
• Normative structure and relationships
  • Includes informative annexes linking the spline filter to the filtration matrix model and the GPS matrix model.

Applications and users

EN ISO 16610-62:2023 is intended for professionals involved in surface texture measurement, analysis and specification:

• Metrology laboratories and calibration facilities performing areal surface measurements.
• Quality and process engineers specifying surface requirements (roughness, waviness) for components.
• Instrument and software developers implementing areal filtering algorithms for profilometers, confocal microscopes and optical profilers.
• Manufacturing sectors where surface topography affects function: bearings, seals, optics, medical devices, and precision machined parts.

Practical uses include extraction of waviness from measured topography maps, setting cut-off wavelengths for areal analyses, and ensuring consistent filtering for GPS-compliant surface specifications.

Related standards

• ISO 16610-1 (overview and basic concepts)
• ISO 16610-21 / ISO 16610-61 (Gaussian profile / areal filters)
• ISO 16610-22 (profile spline filters)
• ISO 16610-60 (areal filter basic concepts)
• ISO/IEC Guide 99 (VIM - metrology vocabulary)

Keywords: EN ISO 16610-62:2023, spline filters, linear areal filters, filtration, GPS, cut-off wavelength, regularization parameter, tension parameter, surface metrology, topography maps.