BS EN ISO 8785:1999 pdf free.GEOMETRICAL PRODUCT SPECIFICATION (GPS) - SURFACE IMPERFECTIONS - TERMS, DEFINITIONS AND PARAMETERS. Introduction BS EN ISO 8785 is a geometrical product specification (GPS) standard and is to be regarded as a general GPS standard (see ISO/TR 14638). It influences the chain links 1 and 2 of the chain of standards for surface imperfections. For more...