In a medical or dental-medical handpiece having a tool, a drive mechanism for the tool has at least one rotary part mounted rotatably by means of a bearing arrangement. The cover is comprised of at least a top layer and a bottom layer structured in a way to form a recloseable aperture. A process stream generated from the separation system and having the normal paraffins is passed to an adsorption unit for the selective adsorption of aromatic compounds from the process stream, thereby producing a purified product. A data quantity converter that converts the quantity of variable data. The sensor system further includes a sensor connected to the generator for receiving power, wherein the sensor is configured to sense the physical characteristic associated with the conveying system.