DIN EN ISO 489:1999-08

The document specifies two test methods for determining the refractive index of plastics. Method A: Refractive method for measuring the refractive index of moulded parts, cast of extruded sheet or film by means of a refractometer. It is applicable to mot only isotropic transparent, translucent, coloured or opaque materials but also anisotropic materials. It is not applicable to powdered or granulated material. Method B: Immersion method (Becke line phenomenon) for determining the refractive index of powdered or granulatet transparent materials by means of a microscope and making use of the Becke line phenomenon. It is applicable to isotropic translucent, coloured or opaque materials as well as anisotropic materials.