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AssigneeMettler-Toledo AG
InventorsChanglin Wang, Fengjin Wang, Jun Xia, Xiaokai Wang, Jürgen Ammann
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Exemplary embodiments of the present invention are directed to methods and devices for detecting open-circuit and short-circuit failure in an electromagnetic (inductive) measurement of the conductivity of liquids and on the sensor and cable wiring. An electromagnetic measurement of the conductivity of a liquid is performed by immersing a sensor into the liquid, wherein the sensor includes at least 2 toroidal cores, one of them carrying an excitation coil and the other carrying an induction coil. When an AC excitation voltage is applied to the excitation coil, an induced current or voltage can be measured in the induction coil which is proportional to the conductivity of the measured liquid.
A method for detecting a failure of a measurement device for inductively measuring the electrical conductivity of a fluid medium with a sensor having at least two toroidal cores, wherein a first toroidal core carries an excitation coil and a second toroidal core carries an induction coil, the sensor is connected to a measuring device having an excitation driving circuit to supply an AC excitation voltage to the excitation coil inside the sensor so that a current or voltage, related to the conductivity of the measured liquid, is induced in the induction coil, said method comprising:
A circuit for detecting a failure of a device for inductively measuring the electrical conductivity of a fluid medium with a sensor, the sensor comprises at least one excitation coil or induction coil, for applying to the fluid medium or receiving from the fluid medium an alternating current, said detection circuit comprising:
Dependencies are inferred from the claim text.