transducer apparatus comprises a transducer housing, a tube, a temperature sensor as well as a temperature sensor. The tube is arranged within a cavity of the transducer housing, in such a manner that an intermediate space is formed between a wall of the transducer housing facing the cavity inner surface and an outer surface of a wall of the tube facing the cavity. Furthermore, the tube is adapted to guide a fluid in its lumen, in such a manner that an inner surface of the wall of the tube facing the lumen is contacted by fluid guided in the lumen. Each of the temperature sensors is formed by means of a temperature detector arranged within the intermediate space as well as by means of a coupling body coupling the respective temperature detector thermally conductively with the wall of the tube and is additionally adapted to register a particular measurement location temperature, and to transduce such into a corresponding temperature measurement signal, namely an electrical measurement signal representing the particular measurement location temperature.