The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 2001
Filed:
Dec. 11, 1997
Ralf Schimmel, Weilmünster, DE;
Stefan Lipfert, Kelkheim, DE;
Joachim Acht, Frankfurt, DE;
Werner Wallrafen, Hofheim, DE;
Mannesmann VDO AG, Frankfurt, DE;
Abstract
A limit-level sensor for measuring level of a liquid has a resistance element which has an electric resistance which suddenly varies a transition temperature which lies above the maximum liquid temperature. The resistance element is first heated by electric current. Thereupon, the electric resistance of the resistance element is measured. When the resistance element is covered with liquid, the heat generated by the electric current is led away so that the temperature of the resistance element is less than its transition temperature. If the resistance element is not covered by liquid, this heat is scarcely led away, so that the temperature of the resistance element remains above the transition temperature.