Talk:Aluminium Oxide Sensor: Difference between revisions

Latest revision as of 17:59, 4 November 2012

text moved to the content page Hschwarz 18:59, 4 November 2012 (CET)

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-Author: [[User:Hschwarz|Hans-Jürgen Schwarz]]<br>
+text moved to the content page [[User:Hschwarz|Hschwarz]] 18:59, 4 November 2012 (CET)
-<br> <br> back to [[Air Humidity Measurement|Air Humidity Measurement]] <br>
-== Abstract  ==
-An oxide layer (Al<sub>2</sub>O<sub>3</sub>) is applied to an aluminium electrode at a few microns thickness. Such layers are always porous and therefore water molecules can be stored. The concentration of the water molecules depends on the ambient air.
-A thin layer of gold, which is permeable to water molecules, is now deposited on the oxide layer. The whole set up works as a capacitor with the oxide film as a dielectric. Its impedance depends on the concentration of the stored water molecules and is measured by an external electronic device. The absorption of water molecules depends on temperature, therefore the temperature of the measurement gas must be either constant or must be determined. The measuring range is typically between -70 to +60°C dew point. The sensor is sensitive towards aggressive gases and shows a drift, therefore it has to be recalibrated. <br> Cermet- Sensors work in a similar way but use a conductive metal-ceramic as a dielectric. They may be more chemically resistant in certain applications.
-<br>
-== Literature<br><br>  ==
-[[Category:Humidity Measurement]] [[Category:Schwarz,Hans-Jürgen]] [[Category:R-SLaue]] [[Category:Bearbeitung]]