The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 24, 2011
Filed:
Apr. 22, 2005
Maximilian Fleischer, Höhenkirchen, DE;
Uwe Lampe, Buxtehude, DE;
Hans Meixner, Haar, DE;
Roland Pohle, Herdweg, DE;
Elfriede Simon, München, DE;
Maximilian Fleischer, Höhenkirchen, DE;
Uwe Lampe, Buxtehude, DE;
Hans Meixner, Haar, DE;
Roland Pohle, Herdweg, DE;
Elfriede Simon, München, DE;
Micronas GmbH, Freiburg, DE;
Abstract
A gas sensor based on a field effect transistor ('FET') evaluates both a change in work function of a gas-sensitive layer of the FET and a change in the capacitance of the layer. Thus, two physically independent signals are read from the gas-sensitive layer, each signal representing a sensitivity to a different gas. This reduces the effect of cross-sensitivities; that is, of one gas on the target gas. The underlying physical mechanisms, the first causing a change in the work function in a reaction with gases and the second causing a change in the capacitance of the sensitive layer, are widely different. Because of this, the two parameters demonstrate different gas sensitivities. If the reactions to both gases are known, the effect of the interfering gas on the sensor signal can be compensated for, and with this the concentration of the target gas can be determined.