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. 30, 1994
Filed:
Oct. 05, 1992
Frank J Koch, Ogdensburg, NY (US);
Leon C Vandervalk, Ogdensburg, NY (US);
David J Beamish, Ogdensburg, NY (US);
De Felsko Corporation, Ogdensburg, NY (US);
Abstract
A gauge probe for a handheld combination coating thickness gauge allows the combination coating thickness gauge to measure both nonferrous coatings on ferrous substrate and nonconductive coatings on conductive nonferrous substrate. The gauge probe enables the combination coating thickness gauge to determine automatically, with a single probe, the substrate characteristics, and to effect a measurement of the coating thickness on that substrate. The technique used to measure coatings on a ferrous substrate utilizes a permanent magnet to provide a constant magnetic flux and a Hall sensor and thermistor arranged to measure the temperature-compensated magnetic flux density at one of the poles of the permanent magnet. The flux density at the magnet pole can be related to a nonferrous coating thickness on a ferrous substrate. The technique used to measure nonconductive coatings on a conductive nonferrous substrate utilizes eddy current effects. A coil near the gauge probe tip is excited by an alternating current oscillating between about 6 MHz and about 12 MHz. The coil sets up eddy currents on the surface of the conducting substrate. The resulting eddy currents set up an opposing magnetic field which in turn have an effect on the excited coil. The eddy current effects on the coil are quantified, and the degree of the eddy current effects on the coil are related to the nonconductive coating thickness on a conductive substrate. The gauge probe detects the substrate type and automatically determines the coating thickness on the detected substrate.