pinnaprofiili

Pinnaprofiili, or surface profile, is a term used in metrology to describe the two-dimensional topography of a surface along a specified line. It represents the vertical deviations of the surface from a reference plane or a mean line over a chosen tracing length. The profile is typically obtained with a profilometer (stylus) or an optical profiler and is used to assess surface quality and its functional properties, such as friction, wear, sealing, and fatigue resistance.

Measurement is usually performed by moving a stylus or sensor along a predetermined path across the surface. The instrument records the surface height as a function of position, producing a profile curve z(x). The profile can be analyzed directly or subjected to filtering to separate short-wavelength roughness from longer-wavelength waviness. An evaluation length is defined to extract meaningful parameters from the profile.

Common 2D profile parameters include Rp (maximum peak height above the reference line), Rv (maximum valley depth below the reference line), and Rz (the average peak-to-valley height over several sampling lengths). Roughness within the profile is often summarized by Ra (arithmetical mean roughness) or Rq (root-mean-square roughness). These parameters are compared against tolerances specified for a part or surface finish.

Relationship to other concepts is important: the measured pinnaprofiili may contain both roughness and waviness, which can be separated through filtering. Pinnaprofiili is distinct from areal surface texture measurements, which describe a surface over an area rather than along a line.

Applications of pinnaprofiili include quality control in manufacturing, evaluation of mating surfaces, and assessment of functional performance in components such as gears, seals, and bearing surfaces. Standards such as ISO 4287 define 2D roughness parameters used in profile analysis.