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:
Sep. 07, 2004
Filed:
Aug. 14, 2002
Michael E. Webber, Culver City, CA (US);
Ronald K. Hanson, Cupertino, CA (US);
Jay B. Jeffries, Palo Alto, CA (US);
The Board of Trustees of Leland Stanford Junior University, Stanford, CA (US);
Abstract
A system and method utilizing a radiation source with a wavelength near 2 &mgr;m (preferably 1993 nm) to measure the presence of ammonia, carbon dioxide and water vapor using spectroscopic techniques and a reduced measurement pressure is provided. Using radiation substantially near 2 &mgr;m enables one to interrogate the P (3) ammonia transition at a frequency of 5016.977 cm , which is isolated from water and carbon dioxide interference; the P(32) carbon dioxide transition at 5017.030 cm , which is isolated from both ammonia and water interference, and a water transition at 5017.100 cm . Moreover, a tunable radiation source that can sweep over the aforementioned ammonia and carbon dioxide and water features can measure the concentrations of all three species simultaneously. Using a sub-atmospheric pressure substantially near 100 Torr decreases the pressure broadening of different spectroscopic transitions, thereby isolating different absorption features, enabling species-specific measurements without interference, yet retaining sufficient peak absorption.