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. 21, 2001
Filed:
Dec. 23, 1998
Robert A. Bauer, South Milwaukee, WI (US);
Richard W. Hirthe, Milwaukee, WI (US);
Mark H. Polczynski, Elm Grove, WI (US);
Martin A. Seitz, Brookfield, WI (US);
James E. Hansen, Oak Creek, WI (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A fluid condition monitor suitable for real time monitoring of a fluid in a fluid system such as on-board vehicle monitoring of engine oil and transmission fluid to determine contamination. A capacitive spaced array electrode probe is immersed in the fluid and an oscillating voltage is applied at a first frequency of at least one hertz and the current I,measured as an analog of the bulk fluid impedance. The voltage is also applied to the probe at a second frequency of less then one hertz and the current I,measured as an analog of the electrode surface impedance. The difference in measured currents &Dgr;I is determined electrically compared with a predetermined threshold value; and, the measured first frequency current I,is compared with an upper and lower limit value for I,determined empirically for the known baseline fluid. If &Dgr;I is below the threshold or I,is not within the upper and lower limits, a fault condition is declared and an indicator is activated to warn that the fluid is not suitable for continued operation of the system. An alternate embodiment includes a fluid level sensor.