Intro To Eddy Current Theory

[Greg_Chase]

If you reposition and re-shape the eddy current-inducing coil so that it horizontally laid out (instead of the vertical orientation), the eddy currents are induced and stretched-out over a larger surface area of the metal. You end up with horizontally-oriented eddy current in the metal layer.

We then position a vertically-oriented static magnetic field. Since the 90 degree cross of electric (eddy) current with a magnetic field results in the Lorentz force, the charged particles in the metal are coherently accelerated by the Lorentz force.

Our horizontally-oriented eddy current coil is fed with very high frequency (RF). The result is - immense accelerations of the charged particles in the metal.

Our test device consists of ten layers of aluminum foil, each layer separated by insulation. The thickness of the aluminum foil has a 'skin depth' for a frequency of 10 Mhz.

Very nice, very clear explanation of eddy currents - thank you!

[anjalisingh]

Thanks a lot sir..
I am Anjali from India🇮🇳

[JClasenCowleyNDT]

What you are going to have to do is to get a "standard" set up with the conditions that you are looking for so that way you can fine tune your instrument to get calibrated for those particular scenarios.

I would start with a higher frequency and then work my way down until I could see all of the indications that I were looking for.

Thanks

Joe

[NaveedKhan-bypr]

great chennal to khow the hvac technology, thank sir.

[JClasenCowleyNDT]

Yes and no, it just really depends on what you are looking for. Eddy Currents can test for discontinuities below the surface of a material, it just has to be set up to do that or else you will not see what you are looking for.

Are you looking for something specific?

[jackzhao]

How to calculate the eddy current and force well and truly？

[lesosbourne]

why not DC or permanent magnets,
also is the effect the same if you rotate the magnets around a fixed
aluminum plate.
Regards Les

[jesseinfinite]

Could you please clarify why the eddy currents are circular?

[hankmancil]

Is X and Y sensitivity the same as Vertical and Horizontal gain?