Patent ID: 8552750

Claim:
A device for the direct measurement of plural parameters of a hydrocarbon based fluid comprising: a sensor comprising a single pair of mutually spaced coaxial electrodes that define a measurement cell that can receive said fluid and be in direct electrical connection with said fluid in said cell, said cell being configured and sized to have a conductivity cell factor of about 0.1 or less and a bulk capacitance of at least 4 pF with said hydrocarbon fluid in said cell; an integrated circuit electrically connected to said sensor to measure the conductivity for said fluid with an AC excitation drive signal; an integrated circuit electrically connected to said sensor to measure the dielectric constant of said fluid with an AC excitation drive signal; and an interface electrically connected between said sensor and both said conductivity and dielectric constant integrated circuits, said interface circuit matching the electronic characteristics of at least said sensor and said dielectric constant integrated circuit, wherein said interface comprises solid state relay switches being optocouplers that multiplex said sensor as an input to both said conductivity and said dielectric constant integrated circuits.