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:
May. 20, 2003
Filed:
Mar. 27, 2001
Mei Li, Dearborn, MI (US);
Roderick I. L. Guthrie, Montreal, CA;
Limca Research Inc., Montreal, CA;
Abstract
Molten metal inclusion sensor probes have a sensing passage through which the molten metal passes, while direct current passes through the passage between two electrodes. The passage of an inclusion through the passage changes the resistance in the path, resulting in a pulse indicating its size, and enabling the number of particles in a sample to be counted. Previously the passage has been cylindrical, with or without a conical entrance, or of randomly smoothed profile produced by melting the probe material. High levels of background noise make pulse detection difficult, and operation is improved by the passage decreasing smoothly in cross-section in the flow direction, preferably with a parabolic or elliptical profile, and preferably with the exit of the same profile. The wall surface is formed to a smoothness of better than 1.016 micrometers (40 microinches), preferably 0.254 micrometers (10 microinches), permitting pre-determination of the optimum testing and conditioning currents required.