Electromagnetic Testing Eddy Current in Brief

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The frequency selected affects not only: (1) the strength of the response from flaws and (2) the effective depth of penetration, but also (3) the phase relationship. Charlie Chong/ Fion Zhang
How do we measure eddy current response? Eddy current response is viewed on an oscilloscope display, showing the impedance response (Z) from the test material, which is affected by factors depending on the specimen and testing conditions. Specimen conditions affecting response: • Electrical conductivity, • Magnetic permeability (unmagnetized ferromagnetic materials can become magnetized, resulting in large changes in impedance), • Specimen thickness - thickness should be limited to less then three times the standard depth of penetration. Testing conditions affecting response: • AC frequency, • Electromagnetic coupling between the coil and the specimen - a small liftoff has a pronounced effect, • Inspection coil size, • Number of turns within the coil itself, • Coil type. Charlie Chong/ Fion Zhang
Page 1 and 2: Electromagnetic Testing Eddy Curren
Page 3 and 4: Figure 1. Schematic of Eddy Current
Page 5 and 6: As a result of eddy currents, a sec
Page 7 and 8: How eddy currents are created and s
Page 9: Conductivity is sensitive to cracks
Page 13 and 14: Thickness changes in a sample can c
Page 15 and 16: There are two basic types of coil p
Page 17 and 18: A differential probe consists of tw
Page 19 and 20: Lift Off Lift-off from paint, coati
Page 21 and 22: Charlie https://www.yumpu.com/en/br
Page 23: Good Luck! Charlie Chong/ Fion Zhan

Electromagnetic Testing Eddy Current in Brief

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