A transducer apparatus comprises a transducer housing, a tube 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. 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. The temperature sensor is formed by means of two temperature detectors arranged within the intermediate space as well as by means of a coupling body coupling the temperature detector thermally conductively with the wall of the tube as well as by means of a coupling body coupling the temperature detector thermally conductively with the temperature detector and is additionally adapted to register a particular measurement location temperature, namely a temperature at a first, respectively second, temperature measurement location formed by means of the respective temperature detector, and to transduce such into a corresponding temperature measurement signal, namely an electrical measurement signal representing the particular measurement location temperature.