ISO 25178 is the first international standard dealing with areal surface texture. It contains several parts among which part 2 defines a set of areal parameters.

Areal parameters are named with a capital S or V letter. They are applied on a primary surface or a scale-limited surface, but their name do not reflect the type of surface on which the parameter is calculated (contrary to 2D parameters).

These parameters quantify the z axis perpendicular to the surface only.

These parameters quantify the lateral information present on the x and y axes of the surface.

These parameters combine the information present on the x, y and z axes of the surface.

These parameters are calculated from the areal bearing ratio curve.

These parameters are calculated from identified features on the surface, after segmentation by watersheds.

Note 1: MountainsMap offers all parameters described in ISO 25178-2.

Note 2: François Blateyron, director of Digital Surf's Mountains Surface Analysis BU and member of ISO TC 213, wrote several articles on ISO 25178:

 ISO 25178 on Wikipedia
 ISO 25178 sur Wikipedia (French)
 New 3D parameters and filtration techniques for surface metrology, Quality Magazine White Paper

ISO 25178-2 can be purchased from the ISO web site: www.iso.ch

These well-known 3D parameters were defined back in the 1990s at Birmingham by the team of Pr Stout. Later, the european project SurfStand improved these parameters by working on the correlation with functional specifications, and prepared the basis for a draft ISO standard.

Mountains® provides also these parameters under the label EUR 15178N which was the reference of the SurfStand european report.

 Back to Surface metrology guide

Other relevant pages:

  Metrology guide
  Mountains® platform
  Standard packages