Abstract: Disclosed herein is a method for determining two or more properties of a blended biofuel fluid sample, the method comprising measuring a complex impedance of the sample at each of a plurality of frequencies to produce a sample data set, determining a biofuel blend percentage of the sample using the sample data set; and determining at least one additional property of the sample based upon the determined biofuel blend percentage. In another aspect, a biofuel blend percentage of the sample can be determined using an algorithm developed using a data gathering and data mining technique relating measured impedance spectroscopy data from a plurality of samples to biofuel blend percentage values determined using a standard analytical measuring method for biofuel blend percentages.

Abstract: Disclosed herein is a sample cell for use in conjunction with an impedance spectroscopy analysis device having two electrodes extending therefrom. The sample cell is attachable to and detachable from the analysis device and includes a housing having an input port for receiving a fluid sample to be tested. The sample cell also includes two spaced apart parallel plates within the housing and in contact with the fluid sample, wherein when the sample cell is attached to the analysis device, each of the two electrodes contacts a respective one of the plates such that an excitation signal can be provided from the analysis device via the electrodes and the plates to excite the fluid sample, and a response signal indicative of the fluid sample can be communicated via the plates and the electrodes to the analysis device.

Abstract: 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.

Abstract: 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 ? of change (slope) of reactance with respect to resistance computed. The value of ? is then compared with values of contamination concentration ? versus ? in a database, and the value of ? determined by interpolation.

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 (?OX) and HPDSC induction time per ASTM D-5483 (MIN) determined from a lookup table of values of TAN, ?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, ?OX or MIN. When the temperature corrected impedance difference ?ZTC reaches 6.5×105 Ohms, the ATF is considered to have reached the end of its useful life.

Abstract: 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 ?dZ of the impedance difference is determined over a time interval and a physiochemical parameter (X) determined when ?dZ is positive from lubricant with known amounts of constituents selected from the group consisting of (a) Phosphorus, Oxygen and Carbon (P—O—C); (b) Phosphorous and double bond Sulphur (P?S); (c) Zincdialkyldithiophosphate (ZDDP); and (d) the Total Base Number TBN by measuring CaCO3 (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 (X1). The value of the selected parameter X when ?dz is negative is determined from a second region of the table of X versus dZ.

Abstract: 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?) and resistive (Z?) impedances are computed for each current measurement and values of Z? 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? is located; and, the angle of depression of a line from the origin through the center of curvature ? is determined from the plot. Samples of lubricant having known concentration of soot are measured and the angle ? 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.

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 (&Dgr;OX) and HPDSC induction time per ASTM D-5483 (MIN) determined from a lookup table of values of TAN, &Dgr;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, &Dgr;OX or MIN. When the temperature corrected impedance difference &Dgr;ZTC reaches 6.5×105 Ohms, the ATF is considered to have reached the end of its useful life.

Abstract: 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.

Abstract: 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.

Abstract: 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.

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 IB 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 Is 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 IB is compared with an upper and lower limit value for IB determined empirically for the known baseline fluid.

Abstract: 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.

Abstract: 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.

Abstract: 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.