Berlin 2005 – wissenschaftliches Programm
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O: Oberflächenphysik
O 15: Postersitzung (Adsorption an Oberfl
ächen, Epitaxie und Wachstum, Organische Dünnschichten, Oxide und Isolatoren, Rastersondentechniken, Zeitaufgelöste Spektroskopie, Methoden)
O 15.65: Poster
Freitag, 4. März 2005, 17:00–20:00, Poster TU D
Surface investigations of single junction thermal converters in the infrared spectral range — •Viktor Schlosser1, Gernot Heine2, M. Garcocz2, W. Waldmann2, and Gerhard Klinger3 — 1Institut für Materialphysik, Universität Wien — 2Bundesamt für Eich- und Vermessungswesen, Wien — 3Institut für Meteorologie und Geophysik, Universität Wien
The ac-dc transfer standard is one of the basic electrical standards, by which the ac voltage and ac current are deduced from their dc counterparts. A well established method is the comparison of electrical power between ac- and dc- voltage by converting the power to force or heat. Converters may be recognised as reference standard and the system is called No-dqac-dc transfer standardNo-dq. Differences in the signal between ac- and dc- power generation depend on frequency and waveform. In the low frequency regime the thermal ripple dominates the error introduced by the thermal converter. Thermocouple measurements of the bulk temperature of a bead of a single junction thermal converter suggest that a significant thermal ripple exists only at frequencies below 20Hz. A scanning infrared radiation imaging set up was used to investigate the bead’s surface. By this method frequency dependent temperature modulations were observed up to frequencies of 200Hz. The experimental method will be presented and the results will be discussed.