Abstract: A measuring arrangement for determining electrical conductivity of a measured liquid, comprising: a container, in which the measured liquid is accommodated, a gradiometer arrangement, comprising an exciter coil, a first receiving coil and a second receiving coil, wherein the first and the second receiving coils are arranged symmetrically relative to the exciter coil, and a measurement circuit embodied to excite the exciter coil for producing an alternating magnetic field passing through the first receiving coil, the second receiving coil and the measured liquid. The receiving coils are influenced in different manner by the magnetic field induced by the alternating magnetic field in the measured liquid and directed counter to the alternating magnetic field. The measurement circuit is furthermore embodied to register an electrical signal of the receiving coils and to derive from such the electrical conductivity of the liquid.

Abstract: A method for determining residual coupling of an inductive, conductivity sensor, in which the conductivity sensor is surrounded by a measured medium and an equivalent impedance of the medium is calibrated with a variable compensation impedance. The variable compensation impedance and the equivalent impedance of the medium act on a measuring coil of the conductivity sensor with a phase shift of 180°. In order to be able to perform a measuring of the residual coupling with a high accuracy of measurement at any time during operation of the conductivity sensor, the variable compensation impedance is varied until an output voltage of the measuring coil of the conductivity sensor assumes a minimum voltage; wherein the minimum voltage corresponds to the residual coupling of the inductive, conductivity sensor.

Abstract: A conductive conductivity sensor, comprising: a probe immersible in a measured medium. The probe has an inner space, which is connected to an environment of the probe via at least one opening leading out from the inner space and in which are arranged two electrodes, which are supplied with an alternating voltage during measurement operation and which have inner surfaces facing into the inner space and outwardly facing outer surfaces covered by insulation, wherein the inner surfaces have edge surfaces adjoining the openings. Measuring characteristics of the conductivity sensor have a smallest possible dependence on objects arranged in the vicinity of the conductivity sensor. At least the edge surfaces adjoining one of the openings have a surface geometry directing thereon beginning or ending, electric field lines in a direction facing away from such opening and into the inner space.

Abstract: An inductive conductivity measurement cell of the invention includes: sending coil, a receiving coil, and a coil support body having an annular, sending coil chamber and an annular, receiving coil chamber, wherein there extends through the coil support body at least one section of a closed media path, which passes through the sending coil chamber and through the receiving coil chamber, characterized in that the coil support body has first connection bores, which extend from a surface of the coil support body to the sending coil chamber and through which the connection lines of the sending coil extend, and second connection bores, which extend from a surface of the coil support body to the receiving coil chamber and through which the connection lines of the receiving coil extend. The connection lines of the sending coil in the first connection bores are shielded from the connection lines of the receiving coil in the second connection bores by the coil support body.

Abstract: A gradiometer for determining electrical conductivity of a medium contained in a containment, comprising: at least a first electrical coil, a second electrical coil and a third electrical coil, wherein the first coil is embodied as a transmitting coil, wherein the second and third coil are embodied as receiving coils; and a holding apparatus. The first, second and third coils are wound on the holding apparatus. The holding apparatus is arranged through a containment opening in a containment wall in such a manner that the first coil is positioned centrally with respect to the containment wall. The second and third coils are arranged mirror symmetrically to the first coil and are inductively coupled with the first coil.

Abstract: A conductive conductivity sensor, comprising: a probe immersible in a measured medium. The probe has an inner space, which is connected to an environment of the probe via at least one opening leading out from the inner space and in which are arranged two electrodes, which are supplied with an alternating voltage during measurement operation and which have inner surfaces facing into the inner space and outwardly facing outer surfaces covered by insulation, wherein the inner surfaces have edge surfaces adjoining the openings. Measuring characteristics of the conductivity sensor have a smallest possible dependence on objects arranged in the vicinity of the conductivity sensor. At least the edge surfaces adjoining one of the openings have a surface geometry directing thereon beginning or ending, electric field lines in a direction facing away from such opening and into the inner space.

Abstract: A measuring arrangement for determining electrical conductivity of a measured liquid, comprising: a container, in which the measured liquid is accommodated, a gradiometer arrangement, comprising an exciter coil, a first receiving coil and a second receiving coil, wherein the first and the second receiving coils are arranged symmetrically relative to the exciter coil, and a measurement circuit embodied to excite the exciter coil for producing an alternating magnetic field passing through the first receiving coil, the second receiving coil and the measured liquid. The receiving coils are influenced in different manner by the magnetic field induced by the alternating magnetic field in the measured liquid and directed counter to the alternating magnetic field. The measurement circuit is furthermore embodied to register an electrical signal of the receiving coils and to derive from such the electrical conductivity of the liquid.

Abstract: A method for determining residual coupling of an inductive, conductivity sensor, in which the conductivity sensor is surrounded by a measured medium and an equivalent impedance of the medium is calibrated with a variable compensation impedance. The variable compensation impedance and the equivalent impedance of the medium act on a measuring coil of the conductivity sensor with a phase shift of 180°. In order to be able to perform a measuring of the residual coupling with a high accuracy of measurement at any time during operation of the conductivity sensor, the variable compensation impedance is varied until an output voltage of the measuring coil of the conductivity sensor assumes a minimum voltage; wherein the minimum voltage corresponds to the residual coupling of the inductive, conductivity sensor.

Abstract: A conductivity sensor for measuring conductivity of a medium surrounding the conductivity sensor includes a first toroidal coil bounding a medium-receiving passageway and serving for inducing an electrical current in the medium, and a second toroidal coil also bounding the passageway and serving for registering a magnetic field produced by the electrical current. At least one of the toroidal coils has a plurality of first conductor segments, which extend in a plane of a multi-ply circuit board, a plurality of second conductor segments, which extend in a second plane of the circuit board, and a plurality of through-contacts, which connect the first conductor segments with the second conductor segments, wherein the first conductor segments, the second conductor segments and the through-contacts form, together, the windings of a toroidal coil.