发明名称 Method and device for non destructive evaluation of defects in a metallic object
摘要 A device for non destructive evaluation of defects in a metallic object (2) by eddy currents, comprises a field emitter (3) for emitting an alternating electromagnetic field at a first frequency fi in the neighbourhood of the metallic object (2), and a magnetoresistive sensor (1) for detecting a response signal constituted by a return electromagnetic field which is re-emitted by eddy currents induced by the alternating electromagnetic field in the metallic object (2). The device further comprises: a driving circuit (230) for driving the magnetoresistive sensor (1) by a current at a second frequency fc which is different from the first frequency fi, so that the magnetoresistive sensor (1) acts as an in situ modulator; a detector for detecting a response signal between the terminals of the magnetoresistive sensor (1); a filter for filtering the response signal detected by the magnetoresistive sensor (1) to keep either the frequency sum (fi+fc) of the first and second frequencies or the frequency difference (fi+fc) of the first and second frequencies, and a processor for processing the filtered response signal and extract eddy current information on defects in the metallic object (2).
申请公布号 US2009206831(A1) 申请公布日期 2009.08.20
申请号 US20090280414 申请日期 2009.04.09
申请人 COMMISSARIAT A L'ENERGIE ATOMIQUE 发明人 FERMON CLAUDE;PANNETIER MYRIAM;BIZIERE NICOLAS;VACHER FRANCOIS;SOLLIER THIERRY
分类号 G01N27/90 主分类号 G01N27/90
代理机构 代理人
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