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:
Oct. 02, 2001
Filed:
Apr. 20, 1999
C. David Lunden, Federal Way, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
A measuring instrument and method for measuring paint and coating thickness on poorly conductive graphite substrates. The instrument uses a microwave amplifier, a measurement cavity, and an optional reference cavity with supporting electronics to measure the apparent changes in the length of the measurement cavity due to the changes in the paint and coating thickness. The measurement cavity resonates when the measurement cavity is set upon the test surface. The oscillating signal is sent through a) directly to a microwave frequency counter, or b) a reference cavity tuned to give the desired slope detection response to cover the paint and coating thickness range allowed. The filtered response of the reference cavity is converted to a dc level signal proportional to paint thickness. It is presumed that the expert user will have access to a PC allowing instant conversion—via a stepped calibration plate—to paint thickness in mils from electrical data.