Fabrication and Characterization of Miniaturized Thermocouples for Measurements in Flows
The measurement of thermal fluctuations is important for the investigation of the transport features of passive and active scalars in fluids. As an addition to the established cold-wire technique we present a thermal sensor based on a miniaturized coaxial thermocouple. The advantage of such a sensor is first of all its size. The active area extends only a few hundreds of square nanometers sitting at the tip of a thin glass rod of less than a micrometer in diameter. The preferred field of application of this sensor are all measurement situations which require a high spatial resolution of temperature measurements for example within the boundary layer –. The sensors coaxial setup results from its fabrication as a micropipette and has the advantage of an intrinsic shielding against external distortions. The glass micropipettes contain a core of platinum and are coated with gold and are fabricated similar to the ones in . Because of its chemically inert coating, these sensors are applicable for detecting temperature fluctuations in a large variety of liquids and gases. The fabrication and characterization of these sensors is presented here.
KeywordsThermal Sensor Glass Micropipette Spectral Noise Density Borosilicate Glass Tube White Noise Background
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