Eaton Corporation

Anne Matthews Brunson

Richard Walter Hirthe

Martin Arthur Seitz

David R Sosnowski

Lian Q Zou

David Lee Wooton

Charles John Koehler

Charles J Koehler

Victor E Shtaida

Sher Schachameyer

Jianxun Hu

Ronald Mark Johnson

A method and apparatus for evaluating and improving the properties of fluid formulations is disclosed. The inventive concept employs impedance spectroscopy (IS) measurements and data analyses to determine IS parameters of fluids representative of a fluid formulation. Correlations are determined between the IS parameters and the properties of the fluids, and a modified or new fluid formulation may be developed responsive to the correlations.

Fluid formulation evaluation and improvement utilizing broad spectrum impedance spectroscopy

A probe having a pair of electrodes is excited with a low A.C. voltage at a relatively high and relatively low frequency and the difference in current measured. The difference dZ between bulk fluid and interfacial impedance is computed from the current difference. The rate of change &#x394;dZ of the impedance difference is determined over a time interval and a physiochemical parameter (X) determined when &#x394;dZ is positive from lubricant with known amounts of constituents selected from the group consisting of (a) Phosphorus, Oxygen and Carbon (P&#x2014;O&#x2014;C); (b) Phosphorous and double bond Sulphur (P&#x2550;S); (c) Zincdialkyldithiophosphate (ZDDP); and (d) the Total Base Number TBN by measuring CaCO(CO3), from a table of the selected parameter X versus dZ in a first region of the table and determining RUL from a table of RUL versus parameter X (X). The value of the selected parameter X when &#x394;dz is negative is determined from a second region of the table of X versus dZ. The rate of change &#x3a8; of X over a time interval is determined and RUL determined from a known value of Xfor the end of the lubricant life.

Method of determining the fluid condition of diesel engine lubricant during real time operation

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Grafton, WI, United States of America

Anne Matthews Brunson