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:
Aug. 15, 2017
Filed:
Nov. 15, 2013
Juergen J. Zach, Menlo Park, CA (US);
Jim Beres, Menlo Park, CA (US);
Erik Olson, Albuquerque, NM (US);
Juergen J. Zach, Menlo Park, CA (US);
Jim Beres, Menlo Park, CA (US);
Erik Olson, Albuquerque, NM (US);
Pentair Thermal Management LLC, Redwood City, CA (US);
Abstract
Embodiments of the invention provide systems and methods for tracking the thermal age of a self-regulating heating cable. Over a time period, current and voltage data for a cable signal are collected, from which spectral information is extracted. The spectral information has a frequency component and an amplitude component. The cable signal is processed to extract a line frequency signature that includes the electrical system's line current frequency and at least some of its harmonics. A ratio of the amplitudes of at least two of the odd harmonics of the line current frequency is calculated. The ratio is compared to an aging curve indicating the thermal age of the cable as a function of the odd-harmonic ratios. The curve may be obtained in a laboratory setting or in the field by characterizing a cable with zero hours of use. The characterizing may include aging the cable to determine the curve.