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. 10, 2002
Filed:
Feb. 12, 1999
Alexei Ermakov, Piscataway, NJ (US);
Barbara Jane Hinch, Edison, NJ (US);
Other;
Abstract
The inventive apparatus is capable of accurate contactless sample conductance measurements. In accordance with the invention, a three coil apparatus for inductive conductance measurements comprises at least three coils, (or inductive devices,) a radio frequency (RF) generating device in conjunction with electronic circuitry for radio frequency amplitude measurement and comparison of radio frequency amplitude signals. The attainable accuracy is improved over that achieved using other conventional non-contact means by processing the differences of RF amplitude signals observed across pairs of sensing coils. Also, this invention does not require more complex RF signal processing, such as analysis of in-phase and quadrature voltage data. In a preferred embodiment, the natural resonance frequencies of the two sensing coils are tuned slightly off the RF driving frequency such that a monotonic response across a wide range of the sample's conductivity is achieved. The sensitivity of the apparatus to low sample conductances is thereby further enhanced.