Patent ID: 11879861
Assignee: ENDRESS+HAUSER CONDUCTA GMBH+CO. KG
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 8:
9. A conductive conductivity sensor, comprising:
four electrodes immersible in a medium, the four electrodes including a first current electrode, a second current electrode, a first voltage electrode, and a second voltage electrode;
a signal generator for generating alternating signals;
a switching device connected to the signal generator, and via which the signal generator is connected in a first switching state to the first current electrode, in a second switching state to the first voltage electrode, and in a third switching state to the second voltage electrode;
an impedance measuring device, including:
a measuring device arranged between the signal generator and the switching device and designed to measure a first electrical variable dependent on a path impedance of the first signal path and a second electrical variable dependent on a path impedance of the second signal path, and
a signal processing device connected to the measuring device and designed to determine the first impedance on the basis of the first electrical variable and the second impedance on the basis of the second electrical variable,
wherein the impedance measuring device is configured to:
measure a first impedance, while, via the signal generator and the switching device operated in the second switching state, an alternating signal is introduced into the medium via a first signal path running via the first voltage electrode through the medium to the second current electrode; and
measure a second impedance while, via the signal generator and the switching device operated in the third switching state, an alternating signal is introduced into the medium via a second signal path running via a second voltage electrode through the medium to the second current electrode; and

a measuring device connected to the first voltage electrode and to the second voltage electrode, wherein the measuring device is designed to:
measure a potential difference between the first voltage electrode and the second voltage electrode while, via the signal generator and the switching device being operated in the first switching state, an alternating signal is introduced via the first current electrode into the medium;
determine a corrected potential difference on the basis of the measured potential difference, the first impedance, and the second impedance; and
determine and make available a measured conductivity on the basis of the corrected potential difference.