Electrochemical Impedance Spectroscopy (EIS) is used in conjunction with continuous glucose monitors and continuous glucose monitoring (CGM) to enable in-vivo sensor calibration. gross (sensor) failure analysis, and intelligent sensor diagnostics and faith detection. An equivalent circuit model is defined, and circuit elements are used to characterize sensor behavior.

A method includes monitoring, via a device including an electrochemical cell, an electrical current that is proportional to an impedance of the electrochemical cell, and responsive to determining that the electrical current satisfies a threshold, measuring, via the device, a plurality of impedances of the electrochemical cell corresponding to a plurality of frequencies. The method further includes determining a charge transfer conductance and a solution resistance based on the plurality of impedances at fewer than four of the corresponding plurality of frequencies and determining the presence of electrochemical interference based on the solution resistance and the charge transfer conductance. The method further includes outputting an alert based on the determination of the presence of electrochemical interference.

A sensor and/or detector having been optimized to produce a rapid rate of change in capacitive reactance and or inductive reactance such that changes in material composition or signal withing the electromagnetic field of the sensor or detecting means will produce a high rate of change in the output signal of the sensing or detecting means.

Methods for determining an electrical conductivity of an operating liquid in an operating liquid container for a motor vehicle. The operating liquid container includes at least one capacitor which is fastened to a container wall of the operating liquid container and has a first electrode and a second electrode opposite said first electrode. A first method determines the electrical conductivity of the operating liquid by means of a frequency-dependent phase progression of the impedance of the at least one capacitor. Another method determines the electrical conductivity of the operating liquid by means of a frequency-dependent capacitance profile of the at least one capacitor. An operating liquid container which is designed for carrying out the methods.

Systems and methods for this disclosure describe systems and methods that are directed to monitoring active clay in water-based drilling fluid may be provided. A method for monitoring active clay concentration while drilling may be provided. The method may include providing a sample of water-based drilling fluid. The method may further include adding methylene blue to the sample in a methylene blue titration. The method may further include performing an impedance measurement on the sample during the methylene blue titration. The method may further include determining an endpoint of the methylene blue titration using a phase angle measurement from the impedance measurement. The method may further include correlating the endpoint to the active clay concentration of the sample. The method may further include determining a treatment for the water-based drilling fluid based on the active clay concentration.

Certain disclosed methods include: transmitting an excitation signal into the MUT and transmitting a reference signal to a set of magnitude and phase (M/P) detectors; receiving the response signal; separately comparing a magnitude and phase for each of the excitation signal and the reference signal with corresponding detection ranges for a first one of the M/P detectors; separately comparing a magnitude and phase for each of the response signal and the reference signal with corresponding detection ranges for a second one of the M/P detectors; iteratively adjusting the excitation signal until the response signal has both a magnitude and a phase within the corresponding detection ranges for the second M/P detector; and iteratively adjusting the reference signal until the reference signal has both a magnitude and a phase within the corresponding detection ranges for the first and the second M/P detectors.

Embodiments of an invention disclosed herein relate to methods for performing formation evaluation of a formation or formation's surrounding to identify and characterize the abundance and morphology of non-ionic conductor grains, “c-grains”, within the formations that are evaluated by formation evaluation (FE) tools. The methods and related systems as disclosed herein are directed to correcting any existing FE logs that can be adversely affected by the presence of c-grains in the detection volume of FE tools, and/or obtaining new FE information that is unavailable by the application of existing FE methods.

This disclosure relates generally to a system and method for real-time non-invasive estimation of food quality within enclosed package. Existing works utilize invasive methods that require direct contact of the food item with the sensors. In the present disclosure, a potential is applied over a plurality of frequencies through the food item contained the enclosed package which includes a plurality of polyethylene layers and a conducting layer arranged between two adjacent polyethylene layers using electrochemical impedance spectroscopy. Values of electrical voltages and the electrical impedances of the food item are then obtained. A plurality of features is derived from the obtained values of the electrical voltages and the electrical impedances using a trained model. The present disclosure estimates the quality of the food item in real-time by co-relating the plurality of derived features with the quality of the food item contained inside the enclosed package.

A fluid sensor includes a tuning fork mechanical resonator including a base and a tine projecting from the base along a longitudinal direction of the tine, and a pair of electrodes disposed on the tine. The base and the tine are formed from a piezoelectric material including lithium tantalate. The electrodes are exposed to a fluid.

Systems and methods are described herein. The method generally includes generating frequency responses of one or more sample fluids having known fluid properties, selecting an equivalent circuit model for modeling the frequency responses, the equivalent circuit model including one or more model elements, calculating an equivalent impedance of the equivalent circuit model, generating a correlation between the one or more model elements and the known fluid properties, measuring an impedance of a drilling fluid, and determining at least one property of the drilling fluid based on the correlation between the one or more model elements and the known fluid properties.