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:
Jul. 15, 2003
Filed:
Sep. 30, 1999
Evren Eryurek, Minneapolis, MN (US);
Steven R. Esboldt, Eagan, MN (US);
Rosemount Inc., Eden Prairie, MN (US);
Abstract
Diagnostic circuitry of a process device is used to detect degradation of a resistive element of the process device while the process device remains online and without an additional power source. The diagnostic circuitry includes a testing circuit and a processing system. The testing circuit is coupled to the resistive element and is configured to apply a test signal to the resistive element. The test signal heats the resistive element and causes the resistive element to generate a response signal. The processing system compares a time constant of the response signal to a corresponding reference to detect degradation of the resistive element.