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. 12, 1989
Filed:
Aug. 31, 1988
Keith Hall, Altrincham, GB;
Philip A Freedman, Hartford, GB;
Elizabeth J Jumeau, Leftwich, GB;
Roger Guilluy, St Bonnet de Mure, FR;
Christiane Pachiaudi, Meyrieu, FR;
VG Instruments Group Limited, Crawley, GB;
Abstract
The invention comprises methods and apparatus for the mass spectrometric determination of the isotopic composition of an element comprised in an analysis gas (that is, a gas comprising the element in elemental form or in the form of a simple compound, e.g., nitrogen or carbon dioxide). First and second flows of a carrier gas (e.g., helium) are simultaneously passed into the mass spectrometer, and samples of analysis gas and a reference gas are respectively introduced into the first and second flows during selected time intervals. The time intervals are selected so that mass spectrometric measurements are made on the analysis gas samples in the absence of any signal from the reference gas samples, and v.v. A preferred embodiment comprises a gas chroatograph through which a sample containing the element is passed, and conversion means to convert the eluting sample into the analysis gas.