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:
Nov. 20, 2001
Filed:
Jun. 11, 1999
Applicant:
Inventors:
Hong T. Sun, Sunnyvale, CA (US);
Peter C. Hsi, Fremont, CA (US);
Assignee:
RAE Systems, Inc., Sunnyvale, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N 2/762 ; G01T 1/18 ;
U.S. Cl.
CPC ...
G01N 2/762 ; G01T 1/18 ;
Abstract
A multiple-channel photo-ionization detector (PID) determines the concentrations of specific gases or classes of gases. The PID includes a UV lamp, an optical window which is divided into multiple zones with each zone producing a UV light beam having a distinctive maximum photon energy. The ionization chamber of the PID includes multiple ion detectors. The PID measures ionization currents and concentrations of gases ionizable by each UV light beam. A method of determining the concentrations and/or identifications of the individual component gases uses differences and/or ratios of measured concentrations or currents.