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: The safety and proper performance of jet aircraft engines requires that any contamination of jet fuel, for example by water or by improper contaminants, be filtered (removed) before delivery of the fuel, through hoses, to the fuel tanks of the aircraft. Coalescing devices and filters in the fuel delivery system are used to attain this result. A typical problem is that filter materials chemically react with surfactants, and this causes the filter subsequently to “disarm” or fail to perform its function of removing water, which can lead to delivery of fuel containing excessive water. A solution to this problem is to pre-test the fuel for such surfactants by feeding a small fuel sample that has been mixed with “challenge water” through a smaller ‘representative’ test filter and monitor the performance. Using a fluorescent dye in the “challenge water,” the amount of water that passes the test filter is detected, compared with a baseline data and fuel quality determination is made.

Abstract: The safety and proper performance of jet aircraft engines requires that any contamination of jet fuel, for example by water or by improper contaminants, be filtered (removed) before delivery of the fuel, through hoses, to the fuel tanks of the aircraft. Coalescing devices and filters in the fuel delivery system are used to attain this result. A typical problem is that filter materials chemically react with surfactants, and this causes the filter subsequently to “disarm” or fail to perform its function of removing water, which can lead to delivery of fuel containing excessive water. A solution to this problem is to pre-test the fuel for such surfactants by feeding a small fuel sample that has been mixed with “challenge water” through a smaller ‘representative’ test filter and monitor the performance. Using a fluorescent dye in the “challenge water,” the amount of water that passes the test filter is detected, compared with a baseline data and fuel quality determination is made.

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).