Unit for the preparation of bituminous material mixture samples. The cover with sealing is equipped with an electric spindle motor to open and close. A window permits to watch the mixing process inside. This window can be replaced by the optional available funnel In addition the cover is provided with connection plugs for gas etc. The constant speed motorized stainless steel mixing drum is equipped with switch to turn left or right (mixing principle synchronised or in counter direction). An electric heating installation at the bottom and walls with PID regulator provides a constant temperature. For de-loading the mixing bowl can be tilted to the front by the installed motor system. The special mixing tool with electric motor and variable speed range is optimized for mixing asphalt samples in smaller and larger quantities.