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:
Sep. 28, 2004
Filed:
Oct. 01, 2002
Jay E. Klevens, Pittsburgh, PA (US);
Process Instruments, Inc., Pittsburgh, PA (US);
Abstract
One aspect of the present invention relates to a digitally controlled resistance standard, comprising a control system, a resistor element, hermetically sealed within an element assembly, a temperature/frequency measuring circuit for measuring the temperature of the resistor element and the frequency of an input signal, a heating/cooling assembly for raising and lowering the temperature of the resistor element a temperature controller for controlling the heating/cooling assembly, and a control system having a CPU. The control system is operable to execute computer instructions for storing the baseline characteristics of the resistor element, retrieve the temperature of the resistor element from the temperature/frequency measuring circuit, determine the actual resistance value of the resistor element, and adjust the actual resistance value of the resistor element to match a target resistance value using the temperature controller. A method for improving the accuracy of a resistance standard is also given.