DIN EN ISO 13565-1:1998-04

The document describes a filtering method for use with surfaces that have deep valleys below a more finely finished plateau with a relatively small amount of waviness. The reference line resulting from filtering according to ISO 11562 for such surfaces is undesirably influenced by the presence of the valleys. The filtering approach described in the document suppresses the valley influence on the reference line such that a more satisfactory reference line is generated.