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:
Aug. 11, 1992
Filed:
Dec. 26, 1989
Applicant:
Inventors:
Kiwao Seki, Katsuta, JP;
Koji Tsutsuta, Katsuta, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ; G01R / ;
U.S. Cl.
CPC ...
324439 ; 324444 ; 324709 ; 324713 ; 324720 ;
Abstract
An electrical conductivity measuring apparatus for measuring the electrical conductivity of liquid has a plurality of electrodes disposed in the liquid contained in a measuring cell, with an a.c. voltage being applied between the electrodes, thereby measuring the electrical conductivity by measuring a current flowing between the electrodes. The apparatus includes a reference a.c. voltage source including adjustment means for varying the magnitude and phase of the signal current, and is designed to cancel the conductivity of background by adding the current from the reference a.c. voltage source to the current from the electrodes.