Abstract: Described herein are systems and methods for improving performance of single-frequency (single-point, single-bin) discrete Fourier transform (DFT) detectors by elimination of systematic errors from the detector output. Calibration procedures known in the art for practical implementations of such detectors do not provide adequate reduction of these systematic errors thus reducing utilization of these detectors in useful applications and products. The described methods, systems and devices allow such detectors to measure both DC and AC signals and, in latter case, considerably expand the operation frequency range without any additional hardware. These methods enable wide practical applications of DFT detectors across diverse variety of fields: from monitoring health of mechanical structures and fluid properties to impedimetric measurements in electrochemistry, monitoring of corrosion and bioimpedance.

Abstract: Described herein are systems and methods for improving performance of single-frequency (single-point, single-bin) discrete Fourier transform (DFT) detectors by elimination of systematic errors from the detector output. Calibration procedures known in the art for practical implementations of such detectors do not provide adequate reduction of these systematic errors thus reducing utilization of these detectors in useful applications and products. The described methods, systems and devices allow such detectors to measure both DC and AC signals and, in latter case, considerably expand the operation frequency range without any additional hardware. These methods enable wide practical applications of DFT detectors across diverse variety of fields: from monitoring health of mechanical structures and fluid properties to impedimetric measurements in electrochemistry, monitoring of corrosion and bioimpedance.

Abstract: Described herein are devices, systems, and methods for determining the composition of fluids, and particularly for describing the identity and concentration of one or more components of a medical fluid such as intravenous fluid. These devices, systems and methods take multiple complex admittance measurements from a fluid sample in order to identify the identity and the concentration of components of the fluid. The identity and concentration of all of the components of the solution may be simultaneously and rapidly determined. In some variations, additional measurement or sensing modalities may be used in addition to admittance spectroscopy, including optical, thermal, chemical, etc.

Abstract: Described herein are systems and methods for determining the location, composition and concentration of a hydrocarbon containing plume in environmental seawater. These systems and methods disclosed use multiple complex admittance measurements from seawater in order to identify the contents, concentration, and location of the hydrocarbon containing plume. In preferred variations system includes a sensor array that substantially simultaneously records plume location, depth, and composition.

Abstract: Described herein are systems and methods for determining the location, composition and concentration of a hydrocarbon containing plume in environmental seawater. These systems and methods disclosed use multiple complex admittance measurements from seawater in order to identify the contents, concentration, and location of the hydrocarbon containing plume. In preferred variations system includes a sensor array that substantially simultaneously records plume location, depth, and composition.

Abstract: An improved method of packaging a sensor is provided. The method includes the step of affixing a tuning fork to a platform. The tuning fork includes tines comprising one or more surfaces, with each tine further comprising an electrode and a piezoelectric material. An application specific integrated circuit (ASIC) is affixed to the platform. Electrical communication between the ASIC and the electrode of each tine is established for providing stimulus to the tuning fork and for receiving a response signal from the tuning fork. A protective layer is applied to cover the platform and a portion of the tuning fork while maintaining a portion of a surface of each tine free from the protective layer such that the surface can displace the fluid in contact therewith.

Abstract: Described herein are systems and methods for determining the location, composition and concentration of a hydrocarbon containing plume in environmental seawater. These systems and methods disclosed use multiple complex admittance measurements from seawater in order to identify the contents, concentration, and location of the hydrocarbon containing plume. In preferred variations system includes a sensor array that substantially simultaneously records plume location, depth, and composition.

Abstract: Described herein are devices, systems, and methods for determining the composition of fluids, and particularly for describing the identity and concentration of one or more components of a medical fluid such as intravenous fluid. These devices, systems and methods take multiple complex admittance measurements from a fluid sample in order to identify the identity and the concentration of components of the fluid. The identity and concentration of all of the components of the solution may be simultaneously and rapidly determined. In some variations, additional measurement or sensing modalities may be used in addition to admittance spectroscopy, including optical, thermal, chemical, etc.

Abstract: An improved method and assembly, wherein the method generally includes the steps of providing a coated or uncoated sensor element having an exposed sensing surface; attaching the sensor element to a platform so that the exposed sensing surface is spaced from the platform; and optionally applying a protective layer over the platform while maintaining the sensing surface as exposed. The assembly includes a resonator having a free portion with a sensing surface is incorporated onto a platform, components of the sensor are physically shielded from harsh operating conditions, the requisite space is maintained between the free portion of the resonator and the platform, and the sensing surface of the resonator remains exposed for sensing.

Abstract: An improved method and assembly, wherein the method generally includes the steps of providing a coated or uncoated sensor element having an exposed sensing surface; attaching the sensor element to a platform so that the exposed sensing surface is spaced from the platform; and optionally applying a protective layer over the platform while maintaining the sensing surface as exposed. The assembly includes a resonator having a free portion with a sensing surface is incorporated onto a platform, components of the sensor are physically shielded from harsh operating conditions, the requisite space is maintained between the free portion of the resonator and the platform, and the sensing surface of the resonator remains exposed for sensing.

Abstract: Particle and multi-phase system monitoring methods, systems and apparatus are disclosed. Preferred embodiments comprise one or more mechanical resonator sensing elements. In preferred embodiments a sensor or a sensor subassembly is ported to a fluidized bed vessel such as a fluidized bed polymerization reactor.

Abstract: Fluid sensor methods and systems adapted for monitoring and/or controlling distillation operations in fluidic systems, such as batch distillation operations or continuous distillation operations, are disclosed. Preferred embodiments are directed to process monitoring and/or process control for unit operations involving endpoint determination of a distillation, for example, as applied to a liquid-component-switching operation (e.g., a solvent switching operation), a liquid-liquid separation operation, a solute concentration operation, a dispersed-phase concentration operation, among others.

Abstract: A flexural resonator includes a piezoelectric material. At least a portion of an electrode having a first surface and a second surface is embedded in the piezoelectric material such that the piezoelectric material is disposed over and in electronic association with the first and second surfaces of the electrode.

Abstract: A sensor system and method for analyzing a fluid contained within an environmental control system, comprising the steps of providing a system including a passage for containing a thermal change fluid; placing a sensor including a mechanical resonator in the passage; operating the resonator to have at least a portion thereof translate through the fluid; and monitoring the response of the resonator to the fluid in the passage. A preferred sensor includes a tuning fork resonator.

Abstract: A system for monitoring a fluid in an environmental control system includes a mechanical resonator positioned for contacting a thermal change fluid. In some embodiments, the mechanical resonator is positioned in a passage for containing the thermal change fluid. Suitable thermal change fluids include an R-134A refrigerant, a mineral oil, an ester lubricant or a mixture thereof; a superheated refrigerant; or an elevated pressure and elevated temperature vapor, an elevated pressure liquid, a reduced pressure liquid, a reduced pressure vapor and combinations thereof. The mechanical resonator can be a flexural resonator or a torsion resonator. In some embodiments, the mechanical resonator is a tuning fork resonator. Methods of the invention include monitoring a response of the mechanical resonator to the thermal change fluid. In some embodiments, at least a portion of the mechanical resonator is translated through the thermal change fluid and the response of the resonator to the fluid is monitored.

Abstract: Methods for monitoring a fluid composition include placing a mechanical resonator in the fluid composition and oscillating the resonator. The resonator can be a tuning fork resonator having tines oscillated in opposite directions and in opposite phases. A variable frequency input signal can be varied over a predetermined frequency range and oscillate the mechanical resonator at less than 1 MHz. A frequency-dependent resonator response curve can be stored in a computer memory and fitted to a model curve to monitor the fluid. The resonator can be coated with a protective coating. The resonator can be treated with a functionality designed to change a resonance frequency of the resonator after being exposed to a selected target chemical and the resonance frequency monitored to detect presence of the target chemical.

Abstract: An improved system, device and method for characterizing a fluid sample that includes injecting a fluid sample into a mobile phase of a flow characterization system, and detecting a property of the fluid sample or of a component thereof with a flow detector comprising a mechanical resonator, preferably one that is operated at a frequency less than about 1 MHz, such as a tuning fork resonator.

Abstract: A sensor for sensing one or more properties of a vehicle fluid has a tuning fork resonator adapted to contact the fluid. The tuning fork resonator comprises two tines and is operable to oscillate so that the two tines move in opposite phase at a frequency of less than 1 MHz while contacting the fluid to generate a resonator response indicative of one or more properties of the fluid. In another aspect, a sensor includes a substrate and a flexural resonator on the substrate and adapted to contact the fluid. Circuitry for operation of the resonator is on the substrate. The resonator is adapted to receive an input signal and to oscillate while contacting the fluid to generate a resonator response indicative of one or more properties of the fluid. One suitable application for the invention is monitoring the condition of a vehicle engine oil.

Abstract: A method and apparatus for measurement of mass of small sample sizes. The method and apparatus is particularly adapted for providing microbalance measurement of solid materials as part of a combinatorial research program. The method and apparatus contemplate monitoring the response of a resonator holding a sample and correlating the response with mass change in the samples.

Abstract: Fluid monitoring methods, systems and apparatus are disclosed, including a portable subassembly that is in electrical communication with a sensor in contact with the fluid being monitred. Preferred embodiments for the sensor include one or more flexural resonator sensing elements. In preferred embodiments the sensor subassembly is ported to multiple fluidic systems to monitor the fluid properties in an effecient manner.