Abstract: A sensor element for electrically measuring the position of liquid levels, comprising a substrate (2) and a plurality of electrodes (3) that can be contacted individually and that are mounted on the substrate, characterized in that the electrodes comprise sensor-active partial electrodes (5) that are networked with electrical connections (7), with the partial electrodes of two respective electrodes always being positioned opposite one another, separated by a distance, as partial electrode pairs (11) and with the electrode pairs (8) thus formed recurring periodically over the length of the sensor. Quasi-digital measuring methods are derived from the behavior of the impedance of the electrode pairs, whereby the liquid level is measured by detecting a conductivity boundary in a capillary filling.
Type:
Grant
Filed:
July 22, 2002
Date of Patent:
June 15, 2004
Assignee:
Fraunhofer-Gesellschaft zur Foerderung der Angeandten
Forschung E.V.
Inventors:
Thomas Lisec, Bernd Wagner, Hans Joachim Quenzer