Abstract: The invention relates to apparatus for sampling partial quantities from metering devices for granular or pulverized substances into the mixing vessels of plastics processing machines with a metering station having a vessel with a bottom plate and a rotatable metering disc disposed directly above the bottom plate and having apertures for receiving portions of the substance to be metered. A discharge aperture for the portions is disposed under a covering and is in alignment with an inlet aperture in the mixing vessel. In order to sample a portion in order to be able to weight it, the portion is intercepted after it has been separated from the body of the substance in the metering station and while it is being conveyed to the mixing vessel, without moving the mixing station away from the mixing vessel.