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:
Mar. 19, 2002
Filed:
Jun. 29, 1999
Applicant:
Inventors:
William N. Reining, Madison, WI (US);
Marshall J. Bell, Stoughton, WI (US);
Assignee:
Intellectual Property LLC, Cross Plains, WI (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R 2/708 ;
U.S. Cl.
CPC ...
G01R 2/708 ;
Abstract
A conductance sensor uses a high impedance feedback oscillator to drive a single coil at the natural resonant frequency of the coil coupled to a measured material. The amplitude of the driving signal is also feedback controlled. The error signal of the amplitude control yields a measurement of resistance of the measured material. The combination of frequency adjustment and amplitude control eliminates non-resistance impedance effects and amplitude-dependent effects allowing high precision, high sensitivity measurement.