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:
Jul. 02, 1991
Filed:
Dec. 20, 1989
Innes K MacKenzie, Guelph, CA;
Robert J Stone, Dutton, CA;
Tava Corporation, London, CA;
Abstract
A method of measuring a coating thickness applied on a target of constant base material, such coating containing a non-radioactive labelling material having an atomic number higher than 20. The method includes applying a source of constant gamma or x-rays substantially perpendicular from the center of the face of a detector to a target of unknown coating and to a calibration target of the same base material of known coating to cause the labelling material to emit characteristic fluorescent x-ray ranges from 4-90 kev, measuring the fluorescent x-ray and compton yields of the calibration target, measuring the fluorescent x-ray and compton yields of the target of unknown coating, deriving the source-target distance for the unknown coating from the compton yields, deriving the expected fluorescent x-ray of the calibration target of known coating at said distance, and comparing the measured fluorescent x-ray for the unknown coating to the expected fluorescent x-ray derived at said distance to obtain the coating thickness for the unknown coating. The constant source may be eliminated by measuring the ratio of compton and Rayleigh yields. For targets of variable base thickness, the center of the compton profile is measured.