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:
Aug. 20, 1991
Filed:
Jan. 19, 1990
Claude Allaire, Chicoutimi-Nord, CA;
Lionel Talbot, deceased, late of Ville de la Baie, CA;
Alcan International Limited, Montreal, CA;
Abstract
The non-destructive testing of materials, particularly coarse grain materials such as the carbonaceous materials used in the anodes and cathodes of an aluminium smelting furnace, using longitudinal compression waves employs a waveguide to apply the waves to a specimen, the and specimen having a cross-sectional dimension Dg of between 3 and 5 times the material average grain size Dg. Alternatively, or in addition, the waves used preferably are of effective wavelength from about 30Ds to 50Ds. Alternatively, or in addition, the effective wavelength of the waves is preferred to be approximately equal to the length of the sample; the necessary very long samples may be obtained by connecting a plurality of smaller elementary samples end-to-end. The apparatus may include a controllable furnace for cycling the sample to determine the change with temperature of the physical characteristic that is being measured. The methods and apparatus employ relatively low frequencies, in the sonic range, and high powers; although particularly suited for measurements with coarse grain materials they are also very effective with more usual fine grain materials, such as ceramics.