Sa is the mean absolute height within an evaluated areal surface; report the area, scale and evaluation operators.

How do Sa and Ra differ?

Sa describes areal topography whereas Ra describes a profile. They cannot be interchanged without justification of domain and filtering.

Can I analyze a profilometry PDF?

Yes, if the PDF contains machine-readable text from which parameters can be extracted. Scanned documents require OCR.

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2D roughness and 3D surface topography

ISO 25178 · ISO 21920 · Sensofar S neox 6 · Sa · Sq · Ssk · Sku · Sdr