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. 14, 2000
Filed:
Mar. 16, 1999
Applicant:
Inventor:
Kenneth R Smith, Sunnyvale, CA (US);
Assignee:
Geometrics, San Jose, CA (US);
Primary Examiner:
Int. Cl.
CPC ...
G01N / ; G01K / ;
U.S. Cl.
CPC ...
324694 ; 324683 ; 324709 ; 324639 ;
Abstract
Material resistivity measuring apparatus includes a transmitter for transmitting a measurement frequency current through the material to a receiver spaced from the transmitter. The transmitter includes a power amplifier wherein the measurement frequency current is amplified in discrete steps depending upon resistivity of the material. The current level of the transmitter is transmitted to the receiver by modulating the measurement frequency current by a modulation signal whose phase is indicative of power level. The measurement frequency current can be modulated by a second modulating signal which provides a reference phase for the first modulating signal.