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:
Apr. 16, 1991
Filed:
Oct. 12, 1989
Applicant:
Inventors:
Koji Tsutsuta, Katsuta, JP;
Kiwao Seki, Katsuta, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
324444 ; 324439 ; 324613 ; 324715 ;
Abstract
A conductivity detector includes an A.C. voltage supply and control circuit for applying a pair of electrodes disposed within a cell filled with electrolyte with a predetermined A.C. voltage and a correction signal generating circuit for generating a A.C. reference signal. At an auto zero adjustment operation, an output A.C. current signal flowing through the electrolyte is detected and the A.C. current is added to the A.C. reference signal. In advance of measuring conductivity, the amplitude of the A.C. reference signal is corrected until the resultant signal of the A.C. output current and the A.C. reference signal reduces to zero.