Abstract: A method and instrument for comparing the dielectric properties of a flowing stream of fluid with the dielectric properties of a reference fluid in which a uniquely configured multi-capacitor sensor, formed of a first pair of capacitors having like dielectric spaces within which the reference fluid is maintained under non-flow conditions as the dielectric material and a second pair of capacitors having like dielectric spaces within which a sample portion of the flowing stream of fluid is continuously passed as the dielectric material, comprises all of the capacitance elements of a Wheatstone bridge circuit in a single cellular unit in which the capacitive elements are all subjected to the same sample fluid, temperature and pressure environment and which is not sensitive to stray capacitances. Each pair of capacitors forms opposing sides of the Wheatstone bridge circuit.

Abstract: A capacitive type pressure, force or displacement sensing transducer comprised of a mating pair of spaced dielectric elements each carrying a pair of capacitive elements forming two like capacitors of variable capacitance value depending upon the variable spacing distance between the dielectric elements and two like capacitors of fixed capacitance value. The pair of variable value capacitors and pair of fixed value capacitors comprise all of the capacitance elements of a Wheatstone bridge circuit in a single structural unit in which such capacitive elements are all subjected to the same temperature and pressure environment and which is not sensitive to stray capacitances. Each pair of capacitors forms opposing sides of the Wheatstone bridge circuit.

Abstract: A method for measuring the level or volume of a fluid within a fluid storage vessel which comprises: providing a multi-capacitor fluid level sensor formed of a pair of capacitors of fixed and substantially like capacitive value and two capacitors having like open dielectric spaces for receiving varying levels of the fluid within the vessel and with the fluid in the spaces consisting of a pair of capacitors of variable capacitive value; connecting the four capacitors of the sensor together to form the four capacitive sides of a Wheatstone bridge circuit; applying a source of alternating current of constant voltage and set frequency across the bridge circuit to a first set of bridge terminals at opposite corners of the bridge, each of such terminals located between a fixed capacitor and a variable capacitor of the sensor; interrogating the bridge circuit through a detection circuit connected across the bridge to a second set of bridge terminals independent of said first set of terminals and at opposite corners

Abstract: A system for measuring the level or volume of a fluid within a fluid storage vessel which comprises: a multi-capacitor fluid level sensor formed of a pair of capacitors of fixed and substantially like capacitive value and a pair of capacitors having like open dielectric spaces for receiving varying levels of the fluid within the vessel. The four capacitors of the sensor are connected together to form the four capacitive sides of a Wheatstone bridge circuit. A source of alternating current of constant voltage and set frequency is applied across the bridge circuit to a first set of bridge terminals at opposite corners of the bridge, each of such terminals located between a fixed capacitor and a variable capacitor of the sensor. A detection circuit is connected across the bridge to a second set of bridge terminals (independent of said first set of terminals) and at opposite corners of the bridge, each of such terminals located between a fixed capacitor and a variable capacitor of the sensor.

Abstract: A capacitive type pressure sensing transducer comprised of two dielectric elements bearing four like plates or discs of conducting material and two like conductive pressure sensitive diaphragms which together form two like plate type capacitors of fixed capacitance value and two like plate type capacitors of variable capacitance value. The pressure sensitive diaphragms span like recessed areas in one face of one of the dielectric elements to form two like pressure chambers. The four conducting discs are positioned as matching pairs of capacitive plates on each side of the other dielectric element and together form the two fixed value capacitors. The pressure sensitive diaphragms and one of the conducting disc pairs are aligned to form the two variable value capacitors with their capacitance value depending upon the variable spacing distance of the diaphragms from the aligned discs in response to pressure applied to the diaphragms.

Abstract: A capacitive type pressure sensing transducer comprised of a housing having a pressure sensitive element which interfaces with an applied pressure force to be sensed and measured and which moves in response to force changes to vary the volume of the housing in direct relation to such changes. The housing is filled with a fluid which is in fluid flow communication with a multi-capacitor fluid level sensor. The sensor is formed of a first pair of plate type capacitors of like fixed capacitive value and a second pair of plate type capacitors having like open dielectric spaces for receiving varying levels of fluid from the transducer housing in response to changes in the volume of the housing. Thus, a change in pressure applied to the pressure sensitive element of the transducer produces a corresponding change in the fluid level within the dielectric spaces of the second pair of capacitors of the sensor and a corresponding change in the capacitance value of such capacitors.

Abstract: A manometric method and instrument for the continuous detection and measurement of differential pressures which includes a uniquely configured multi-capacitor sensor system. The sensor system is formed of a first pair of plate type capacitors having like dielectric spaces within which a first strata of fluids is maintained and subjected to one pressure force and a second pair of plate type capacitors having like dielectric spaces within which a second strata of fluids is maintained and subjected to another pressure force. The dielectric spaces of each pair of capacitors are interconnected at their lower ends so that the pairs of dielectric spaces form the legs of a classic U-tube manometer whereby the first strata of fluids and the second strata of fluids assume equilibrium positions within their respective dielectric spaces in relation to the densities of such fluids and the respective applied pressure forces.

Abstract: A tubular shaped fluid level or fluid volume sensor for mounting in a fluid storage vessel for sensing the level or volume of the fluid within the vessel which comprises: a first pair of like electrically conductive capacitor elements each formed to present two electrically connected capacitive plate areas, the capacitor elements being spaced from one another and shaped and arranged to generally define together the outer periphery of the tubular sensor; and a second pair of like electrically conductive capacitor elements each formed to present two electrically connected capacitive plate areas, the second pair of capacitor elements being positioned within and spaced from the first pair of capacitor elements and being spaced from one another and shaped and arranged to generally define together the inner periphery of the tubular sensor.

Abstract: A fluid level or fluid volume sensor or probe for mounting in a fluid storage vessel for sensing the level or volume of the fluid within the vessel which is comprised of four like electrically conductive capacitor elements each formed to present two electrically connected capacitive plates disposed in angular relation to each other. Electrical insulating material constitutes centrally located means for mounting the capacitor elements in fixed spaced relationship from one another around such mounting means and for positioning the elements so that each capacitive plate thereof defines with a capacitive plate of the next adjacent capacitor element a dielectric space therebetween whereby the mounted capacitor elements together form four like dielectric spaces. Material of known constant dielectric value fills two of the dielectric spaces thereby forming with their respective space defining capacitive plates two capacitors of known fixed and substantially like capacitive value.