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:
Feb. 01, 2005
Filed:
Dec. 13, 2002
Richard W. Hirthe, Milwaukee, WI (US);
Sher Schachameyer, Mequon, WI (US);
Lian Q. Zou, Glendale, WI (US);
Victor E. Shtaida, Franklin, WI (US);
Richard W. Hirthe, Milwaukee, WI (US);
Sher Schachameyer, Mequon, WI (US);
Lian Q. Zou, Glendale, WI (US);
Victor E. Shtaida, Franklin, WI (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A tubular probe having annularly spaced electrodes is immersed in ATF and sequentially excited with an alternating voltage at a relatively high and low frequency. The current is measured at both frequencies and the difference in impedance computed; and, the differential impedance is corrected for temperature and the corresponding value of one of TAN per ASTM D-669, Delta Oxidation per ASTME-168 (ΔOX) and HPDSC induction time per ASTM D-5483 (MIN) determined from a lookup table of values of TAN, ΔOX and MIN versus impedance differential for known fluid conditions. The remaining useful life (RUL) may then be computed from determined present value of TAN, ΔOX or MIN. When the temperature corrected impedance difference ΔZreaches 6.5×10Ohms, the ATF is considered to have reached the end of its useful life.