Eddy current inspection technique

A current and eddy current technology, used in electromagnetic measurement devices, electrical/magnetic thickness measurement, measurement devices, etc., can solve the problems of local wall thickness reduction, inability to detect corrosion points, and size increase
CN1544932AInactive Publication Date: 2004-11-10SHELL INT RES MAATSCHAPPIJ BV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
SHELL INT RES MAATSCHAPPIJ BV
Publication Date
2004-11-10
Estimated Expiration
Not applicable · inactive patent

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Abstract

Device (9) for inspecting an object (2) of electrically conductive material, comprising a non-static-signal transmitter for generating an electromagnetic field in the object (2), and a receiver (20, 21) for measuring the variations of the eddy current generated by the non-static electromagnetic field and for producing a signal representing the decay of the eddy current, wherein the non-static-signal transmitter comprises at least two laterally spaced-apart emitters (11, 12) for emitting an electromagnetic field, which emitters (11, 12) are, during normal operation, so driven that the resulting electromagnetic field in the central region (26), between the emitters (11, 12), is intensified.
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Description

[0001] This application is a divisional application of the application with the application number 97196272.3, the application date is July 11, 1997, and the invention name is "eddy current detection technology". technical field

[0002] The present invention relates to techniques for detecting objects made of conductive materials. The technical term "detecting an object" used in this specification and claims refers to measuring the thickness of an object, detecting whether there is a subsurface crack in an object, detecting the non-conductive Perform technical operations such as measuring the thickness of a layer of non-reactive material. Such objects may be, for example, container walls, pipe walls, and the like. Background technique

[0003] The effective thickness of objects such as steel vessels, water pipes and tanks may change locally due to external or internal corrosion. For objects covered with a layer of insulating material, if the corrosion condition is to be d...

Claims

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