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:
Jan. 30, 2007
Filed:
May. 04, 2004
Masumi Sakai, Kyoto, JP;
Kazuo Nagasawa, Kyoto, JP;
Masumi Sakai, Kyoto, JP;
Kazuo Nagasawa, Kyoto, JP;
Shimadzu Corporation, Kyoto, JP;
Abstract
An atomic absorption spectrophotometer including a self reverse type hollow cathode lamp and a photomultiplier tube further includes a preliminary tester for measuring a strength of a signal L when a smaller current is supplied to the hollow cathode lamp and a strength of a signal H when a larger current is supplied while a voltage V applied between a cathode and an anode of the photomultiplier is changed. It also includes an optimal voltage detector for detecting a value V0 of the voltage V at which a super ratio U (which is defined as a ratio of a first ratio L0/H0 to a second ratio L1/H1) is closest to unity under a condition that two values V1 and V0 of the voltage V are arbitrarily chosen so that a ratio H1/H0 or a ratio L1/L0 is a predetermined value. The value V0 is used in the following proper measurement of a sample analysis to apply voltage V to the photomultiplier tube of the photometric detector, where a larger current and a smaller current are alternately supplied to the hollow cathode lamp to perform the background correction. This automatically improves the accuracy of the background correction.