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:
Mar. 21, 2000
Filed:
Jun. 22, 1998
Erich Becker, Marl, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
The invention relates to a method according to the eddy-current testing principle, and to a device for determining the thickness of an electrically conductive protective layer which is applied to an electrically conductive base material. The electrical conductivities of the protective layer and of the base material are different from each other. An excitation coil through which a high-frequency electric current is passed is brought near to the protective layer, so that an electric eddy current is produced in the protective layer and possibly in the underlying base material. A parameter related to the impedance of a probe coil is determined and is used as a basis for determining the thickness of the protective layer, for example by comparison with known reference values. The frequency of the high-frequency electric current is selected in such a way that the thickness of the protective layer is determined unambiguously for a ratio of the electrical conductivities of between 0.7 and 1.5.