Eaton Corporation

Marquette University

Charles J Koehler

Richard Walter Hirthe

Martin Arthur Seitz

Don D Vaughan

David R Sosnowski

David Lee Wooton

Lian Q Zou

Victor E Shtaida

Anne Matthews Brunson

Sher Schachameyer

Patrick J Dupies

Impedance spectroscopy is used to determine values associated with properties of a substance such as a fluid. In some embodiments, the present invention is applied to engine lubricants. A spectral matrix is constructed that comprises data taken from spectral plots. Also constructed is a result matrix comprising known quantities of a plurality of fluid constituents. A known analytic technique is performed on the spectral matrix to identify at least one principal component having significant influence on the spectral matrix. A reduced spectral matrix, wherein each column in the reduced spectral matrix is associated with a principal component having significant influence on the spectral matrix, is next created. A statistical technique uses the reduced spectral matrix and the result matrix to create at least one prediction equation. The prediction equation is used to predict at least one property in a second substance in situ.

Fluid condition monitoring using 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

A probe having a pair of closely spaced electrodes is immersed in the lubricant and one electrode is excited with a relatively low voltage AC current. The frequency is swept over a range of about 1-10,000 Hertz and the current and phase angle measured at selected frequency intervals. The reactive (Z&#x2033;) and resistive (Z&#x2033;) impedances are computed for each current measurement and values of Z&#x2033; plotted as a function of Z' as a Nyquist plot. The center of curvature of the plot between the origin and the minimum value of Z&#x2033; is located; and, the angle of depression of a line from the origin through the center of curvature &#x398; is determined from the plot. Samples of lubricant having known concentration of soot are measured and the angle &#x398; determined for each sample. The angle is then plotted as a function of soot concentration and a smooth curve fitted to the data plots. The curve may be programmed into a microcomputer to be used with the sensor for real time determination of soot concentration.

Detecting soot during real time operation in diesel engine lubricant

A system to sense changes in the state of an ion exchange resin bed which includes first and second current electrodes spaced from each other, a first electrical circuit electrically connecting the current electrodes and designed to be connected to a source of alternating current, and also including first and second voltage probes spaced from each other and located approximately between said first and second current electrodes with a wire connecting voltage probes. A second electrical circuit consists of the first and second voltage probes, the wire and the portion of the resin bed lying between said voltage probes so that when the first electrical circuit is energized by the source of alternating current a voltage is induced in the second electrical circuit which corresponds to the state of the resin bed located between the first and second voltage probes.

Method and apparatus to sense changes in the state of a resin bed

Growing community of inventors

Milwaukee, WI, United States of America

Charles J Koehler