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:
Aug. 19, 2008
Filed:
Apr. 28, 2006
Bert Willing, Blonay, CH;
Markus Kohli, Grandson, CH;
Andreas Seifert, Denens, CH;
IR Microsystems SA, Lausanne, CH;
Abstract
A method for etalon suppression in a gas detection device by determining an etalon fringe period during a calibration step without gas in dependency of the DC drive current. A measuring signal which is a function of the gas absorption and substantially independent of an intensity modulation of an initial light signal at an initial frequency (f) is generated by determining a first pre-measuring signal when the laser source is operated at the center of the gas absorption peak, a second pre-measuring signal when the laser source is operated with a DC drive current below the gas absorption peak of the gas to be detected, and a third pre-measuring signal when the laser source is operated with a DC drive current above said gas absorption peak, with a difference between said DC drive currents which corresponds to the etalon fringe period determined in a calibration step before. The final measuring signal is determined as the difference between the first pre-measuring signal and the arithmetic mean of the second pre-measuring signal and the third pre-measuring signal.