Abstract: A sensor for measuring conductivity of a fluid containing dissolved ions, particularly for measuring conductivity of salt water, features a cylindrical tube (57) of poorly conductive material such as glass, a first electrode (51A) and a second electrode (51B) inside the tube, connected together (56) to maintain a common electrical potential, a first transformer (52,53) concentrically arranged around the tube (57) to drive current through the fluid in the tube, and a second transformer (54, 55) arranged to sense a value of the current flowing in the fluid, and a digital processing circuit (62) coupled to receive an output signal of the second transformer, and to derive therefrom a value representing the conductivity of the fluid. The sensor is adapted to be towed behind a research ship, or to be deployed on an autonomous underwater vehicle (AUV) or the like. Current signals are preferably processed by digital switching measurement technology (dMST).

Abstract: A sensor for measuring conductivity of a fluid containing dissolved ions, particularly for measuring conductivity of salt water, features a cylindrical tube (57) of poorly conductive material such as glass, a first electrode (51A) and a second electrode (51B) inside the tube, connected together (56) to maintain a common electrical potential, a first transformer (52,53) concentrically arranged around the tube (57) to drive current through the fluid in the tube, and a second transformer (54, 55) arranged to sense a value of the current flowing in the fluid, and a digital processing circuit (62) coupled to receive an output signal of the second transformer, and to derive therefrom a value representing the conductivity of the fluid. The sensor is adapted to be towed behind a research ship, or to be deployed on an autonomous underwater vehicle (AUV) or the like. Current signals are preferably processed by digital switching measurement technology (dMST).

Abstract: A sensor for measuring conductivity of a fluid containing dissolved ions, particularly for measuring conductivity of salt water, features a cylindrical tube (57) of poorly conductive material such as glass, a first electrode (51A) and a second electrode (51B) inside the tube, connected together (56) to maintain a common electrical potential, a first transformer (52,53) concentrically arranged around the tube (57) to drive current through the fluid in the tube, and a second transformer (54, 55) arranged to sense a value of the current flowing in the fluid, and a digital processing circuit (62) coupled to receive an output signal of the second transformer, and to derive therefrom a value representing the conductivity of the fluid. The sensor is adapted to be towed behind a research ship, or to be deployed on an autonomous underwater vehicle (AUV) or the like. Current signals are preferably processed by digital switching measurement technology (dMST).

Abstract: Disclosed is a system for suppressing vibration and noise mitigation in structures such as blades in turbomachinery. The system includes flexible piezoelectric patches which are secured on or imbedded in turbomachinery blades which, in one embodiment, comprises eight (8) fan blades. The system further includes a capacitor plate coupler and a power transfer apparatus, which may both be arranged into one assembly, that respectively transfer data and power. Each of the capacitive plate coupler and power transfer apparatus is configured so that one part is attached to a fixed member while another part is attached to a rotatable member with an air gap therebetween. The system still further includes a processor that has 16 channels, eight of which serve as sensor channels, and the remaining eight, serving as actuation channels. The processor collects and analyzes the sensor signals and, in turn, outputs corrective signals for vibration/noise suppression of the turbine blades.

Abstract: A sensor, a system of direct measurement using that sensor, and a method of direct and simultaneous measurement of conductivity and dielectric constant of a fluid, particularly high impedance, hydrocarbon-based fluids. The sensor has a cell that holds the fluids to be measured between a single pair of coaxial, bare metal electrodes connected through interface circuitry to measurement circuitry preferably implemented in one or several IC's. The sensor has a mutually compatible electrode geometry that provides both the correct cell constant for measurement of conductivity of hydrocarbons fluids (typical range 0-100,000 pS/cm), and a bulk capacitance (for use in dielectric constant measurement) in the range of measure of readily available low cost commercial IC's (having a typical capacitance measurement span of <10 pF, with a total bulk capacitance at the chip of <20 pF).

Abstract: A sensor, a system of direct measurement using that sensor, and a method of direct and simultaneous measurement of conductivity and dielectric constant of a fluid, particularly high impedance, hydrocarbon-based fluids. The sensor has a cell that holds the fluids to be measured between a single pair of coaxial, bare metal electrodes connected through interface circuitry to measurement circuitry preferably implemented in one or several IC's. The sensor has a mutually compatible electrode geometry that provides both the correct cell constant for measurement of conductivity of hydrocarbons fluids (typical range 0-100,000 pS/cm), and a bulk capacitance (for use in dielectric constant measurement) in the range of measure of readily available low cost commercial IC's (having a typical capacitance measurement span of <10 pF, with a total bulk capacitance at the chip of <20 pF).

Abstract: A system for determining a property, such as conductivity, of a material in which a sensor provides a square wave sensor output signal the value if which is selected to the proper in response to a square wave driver signal. The sensor output signal is compared with a feedback signal to produce an error signal. A forward circuit responds to the error signal and provides an in-phase component thereof which is integrated to provide an integrated DC output signal. A feedback signal provides an in-phase square wave feedback signal the peak-to-peak amplitude of which has a precisely selected relationship with the integrated DC output signal for comparison with the square wave sensor output signal to reduce the error signal to zero. The integrated DC output signal can be digitized and suitably processed to provide a signal which represents the property of the material to a high degree of accuracy.