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DY: Dynamik und Statistische Physik

DY 46: Poster

DY 46.64: Poster

Donnerstag, 11. März 2004, 16:00–18:00, Poster D

Fluctuation Measurements of a Passive Scalar with Miniaturized Thermocouples — •Marco Munzel, J. Peinke, and A. Kittel — Carl von Ossietzky University of Oldenburg, Faculty of Physics, 26111 Oldenburg, Germany

The measurement of thermal fluctuations is important for investigating transport features of a passive and active scalar in fluids. We present a thermal sensor based on a miniaturized thermocouple. Its coaxial setup results from the fabrication as a micropipette normally used in neurobiology. The glass micropipettes contain a core of platinum or constantan wire and are coated with gold. The achieved tip diameters are 1µm and less which enhance the spatial and temporal resolution significantly. Because of their chemically inert coating, these sensors are applicative for detecting temperature fluctuations in large variety of liquids and gases. The sensors were tested in turbulent free-jets of heated water and air. The presented results are compared to a commercially availiable cold wire setup.