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:
Dec. 12, 2000
Filed:
Oct. 05, 1998
Rosario C Sausa, Bel Air, MD (US);
The United States of America as represented by the Secretary of the Army, Washington, DC (US);
Abstract
A laser-based photoacoustic sensor performs trace detection and differentiation of atmospheric NO and NO.sub.2 in order to obtain respective concentrations for NO and NO.sub.2 using photoacoustic spectroscopy. The device of the invention employs a single, pulsed laser having two outputs near 454 nm and 227 nm, respectively, to irradiate a sample vapor, the sample vapor being collected by a hand-held wand. A photoacoustic response from both NO and NO.sub.2 is detected using microphone detectors, is converted into electrical signals, and is analyzed using a microcomputer. The results of the analysis--the respective concentrations of NO and NO.sub.2 in the sample vapor--are displayed on a digital oscilloscope. Preferably, the electrical signals are amplified prior to analysis, and a boxcar integrator is used to sample and average the electrical signals during the analysis operation.