Eaton Corporation

USA As Represented by Secretary of the Navy

Marquette University

Richard Walter Hirthe

Martin Arthur Seitz

David Lee Wooton

Charles J Koehler

David R Sosnowski

Lian Q Zou

Mark H Polczynski

Michael D Frederickson

Alex E Cragoe

Jeff K Latham

Patrick D Riggs

Mohammad N Amin

Anthony L Delieto

Paul G Rops

Victor E Shtaida

Sher Schachameyer

Robert A Bauer

Anne Matthews Brunson

James E Hansen

Don D Vaughan

Steven R Schachameyer

Peter J McGinnis

Charles John Koehler

Francis Christopher Edrozo

Jianxun Hu

Ronald Mark Johnson

Patrick J Dupies

A system and method for monitoring and controlling the properties of fluids is disclosed. The inventive concept employs impedance spectroscopy (IS) measurements, and is suitable for real-time, in situ, monitoring and quality control operations, such as quality control during the manufacture of blended lubricants. IS data are obtained for three or more frequencies, where the lowest frequency is less than 1 Hz and the highest frequency is greater than 1 Hz. These data may be interpreted according to statistical techniques such as Principal Component Regression, analytical techniques such as equivalent circuit modeling, or by a combination thereof. The data analysis provides characteristics, or IS signatures, relating to the properties of the fluid. IS signatures for a test fluid are compared to IS signatures for calibration fluids to determine whether the properties of the test fluid fall within specified limits. Quality control adjustments to the test fluid properties may be performed based on the IS signatures.

Fluid quality control using broad spectrum impedance spectroscopy

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

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

An impedance spectroscopy technique and system for detecting in real time engine coolant contamination in lubricant. A probe is disposed in the lubricant and the probe excited with an a.c. voltage frequency sweep over a selected frequency range. The current and current phase angle are measured at selected frequency intervals and the reactance and resistance computed and plotted at each frequency internal as Nyquist plots. The Nyquist minimum is determined at various lubricant temperatures and a database compiled. The probe is then excited in-situ and current measurements taken for a selected frequency lower than the Nyquist minimum to insure measurement of electrode surfaces characteristics. The reactance and resistance are then computed and the angle &#x398; of change (slope) of reactance with respect to resistance computed. The value of &#x398; is then compared with values of contamination concentration &#x3a8; versus &#x398; in a database, and the value of &#x3a8; determined by interpolation.

Detection of coolant contamination in lubricating fluids

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 (&#x394;OX) and HPDSC induction time per ASTM D-5483 (MIN) determined from a lookup table of values of TAN, &#x394;OX and MIN versus impedance differential for known fluid conditions. The remaining useful life (RUL) may then be computed from determined present value of TAN, &#x394;OX or MIN. When the temperature corrected impedance difference &#x394;Zreaches 6.5&#xd7;10Ohms, the ATF is considered to have reached the end of its useful life.

Monitoring automatic transmission fluid condition in real time

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 plug for insertion through the wall of a vessel filled with fluid to be monitored has an extension immersed in the fluid which has a pair of wire electrodes helically wound thereon in spaced arrangement. The electrodes are wound at a uniform pitch in one embodiment and wound with regions of closely and widely spaced pitches in another embodiment. In a third embodiment, the electrodes are helically wound in spaced parallel arrangement at a pitch greater than the spacing of the pair. A thermistor is disposed on the extension for providing a fluid temperature signal. The electrodes are excited sequentially by a low voltage at a fractional Hertz (low) frequency and a (high) frequency of at least one Hertz and the current and temperature are measured. The impedance and differential impedance are computed from the measured currents. From stored values of the differential impedance as a function of temperature for various known fluid conditions, the condition of the fluid is determined; and, if greater than a predetermined threshold, an alarm is activated and/or the fluid condition displayed.

Monitoring fluid condition with a spiral electrode configuration

A method for real time monitoring fluid in a vessel with a probe having a pair of electrodes immersed in the fluid. The disclosed probe has the electrodes arranged helically on a rod, sized and configured for insertion in an engine dipstick hole. Preferably, the probe has spiral electrode winding up regions different pitch to provide improved impedance response at low fractional Hertz and high (at least one Hertz) frequencies of excitation. In one version with alternating voltage the difference in current magnitude measured at the low and high frequencies is compared with stored known values for known fluid conditions and an electrical signal indicative of fluid condition is generated. Examples with engine drain oil and heavy duty transmission lubricant fluid are presented. The impedance properties measured can determine the percentage remaining useful life (RUL) of the fluid. In another version of the method the current phase shift angle is measured at the fractional Hertzian frequency; and, from known values of current phase shift angle of the fluid, at various conditions, the condition of the fluid determined. The differential current measured and the measured phase shift angle may be combined, for example, by the square of the sum of the squares procedure to provide an enhanced impedance change indicator.

Monitoring fluid condition through an aperture

This invention relates to an on-line statistical process control device for solder paste and residues. The invention consists of electronics hardware, software, and probing systems. The electrical hardware of the invention provides voltage and current measurements of solder paste materials, the software of the invention controls the hardware, provides real-time complex, non-linear least squares curve fitting for equivalent circuit analysis, data storage and retrieval of circuit parameters and behavior, and statistical process control tracking and charting. The probing systems of the invention allows for 2, 3, and 4 probe surface and bulk measurements of the solder paste and residues.

Solder paste and residue

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.

Fluid condition monitor

This invention relates to an on-line statistical process control device for solder paste and residues. The invention consists of electronics hardwa software, and probing systems. The electrical hardware of the invention provides voltage and current measurements of solder paste materials, the software of the invention controls the hardware, provides real-time complex, non-linear least squares curve fitting for equivalent circuit analysis, data storage and retrieval of circuit parameters and behavior, and to statistical process control tracking and charting. The probing systems of the invention allows for 2, 3, and 4 probe surface and bulk measurements of the solder paste and residues.

Solder paste and residue measurement system

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

This invention relates to an on-line statistical process control device for solder paste and residues. The invention consists of electronics hardware, software, and probing systems. The electrical hardware of the invention provides voltage and current measurements of solder paste materials, the software of the invention controls the hardware, provides real-time complex, nonlinear least squares curve fitting for equivalent circuit analysis, data storage and retrieval of circuit parameters and behavior, and statistical process control tracking and charting. The probing systems of the invention allows for 2, 3, and 4 probe surface and bulk measurements of the solder paste and residues.

Growing community of inventors

Milwaukee, WI, United States of America

Richard Walter Hirthe