Eddy Current Testing

Eddy current testing
- Physical background
- Eddy current testing with coaxial probes
- Eddy current testing with surface probes
- Practice
Responsible for this video: Prof. Dr.-Ing. Rainer Schwab, Hochschule Karlsruhe - University of Applied Sciences

[@udhayakumara4033]

My search for eddy current article is ends here. No more explanation needed then this. Perfect 👌

[@lucianoventurinifortunato8522]

I would like to congratulate and thank you for doing and sharing this beautiful work, because, in my opinion, this video has a lot of quality.

[@proveItllc]

Very nicely done! =Kudos to the voice-over actor, she pronounced everything correctly and gave the impression she was a true expert in the field. much to think about. The animation was excellent!!

[@ArvindSingh-jr2on]

Amazing, very calculated, very educated, very nicely, very conceptually explained. ....whole team job well done. Keep it up

[@AssmannVerspaning]

Thanks for yet another informative video! I regularly machine EDM notches in calibration blocks for non destructive testing. It's nice to finally understand how eddy current testing works! Danke für das schöne Video - Grüße aus Holland!

[@bijeshable]

I am a faculty of NDT , and I was searching for a good video of ET, and I got it here. Thanks a lot

[@blackcohn]

I hope you guys will keep posting! it is very useful for us.

[@redbarond1]

Excellent video! I really appreciate the superb combination of theoretical animations, alongside laboratory demonstrations. I wish my physics classes were taught half as well as this!

[@liviarios7541]

Very good explanation of the technique. Congratulations and thanks for sharing this knowledge with an easy understanding!

[@raynercoslop]

fantastic video. Absolutely superb editing and narration

[@varungupta5841]

Amazing video. So much of effort has been put into making this.

[@anupamsengupta2]

Beautifully explained !! Thank-You!!!

[@Emilycatloverdoglover]

Very well made videos. Hope your team could do more! Thanks a lot for the info!

[@GarrettXPrime]

Thanks for the clear concise video!

[@QRAC222]

A really great video, thanks!! Now I understand much better!

[@amiruddinr2319]

amazing. Crystal clear animation

[@AmandeepSingh-ye3hy]

Bravo, explained perfectly. thank you

[@juliasager814]

Nicely done! Thank you very much!

[@havocking9224]

Magnificient video, thanks !

[@blackamericanlesbianprofes4357]

I have never seen this version of eddy current, I use the eddy current unit and probes. Very interesting to see another way eddy current can be described but it is confusing to me because it is brand new way of learning this familiar NDI/NDT technique. Thanks for posting.

[@dheyaakadhim8375]

Thanks for your explanatory videoes.

[@joellapaz465]

Wow that's a big current meter. Excellent video

[@prm414]

Very informative, thank you. We use Eddy Current probes to measure the diameter of steel pipe, up to 2.375”, but I wasn’t very sure how it all worked. The pipe is moving at 150ft per minute while being inspected. There are also fixed magnets, magnetising the pipe longitudinally, and MFL sensors for transverse flaw detection, in the inspection head.

[@alvinmc5593]

very nicely done video...thanks for sharing !

[@mehrabamiry4055]

Thanks for the great video.

[@luizintini9396]

Excellent video!

[@vetrivel.k268]

your way of teaching excellent............

[@benevolentbear8213]

Gem of a video! Thank you.

[@vadimkoller6232]

Amazing video! Thank you :)

[@rafpach87]

That was a great video, thanks!

[@dalegriffiths3628]

Useful video for our students - well explained thank you

[@Jim_One-wl4ke]

Awesome ⭐️⭐️⭐️⭐️⭐️5 stars for your well presented video. ❤thanks for sharing. Subscribed

[@pramodmyakal6875]

Quite a perfect demo. very good..

[@ChrisSorgeloos]

Very good. Thank you for this.

[@solomon0o0o0ozz]

Excellent explanation. Thank you.

[@kamranb04]

very nice and well worked presentation.

[@feelingzhakkaas]

Excellent explanation

[@haaahaaai]

Excellent explaining thank you so much

[@erdalozandilek2533]

Thank you so much. This is really good video.

[@ahmedz2011]

incredible explanation

[@mohammedibrahimkhaleelulla9211]

Clear and wonderful, thank u

[@jedaguilar3459]

Thank you so much, this helps me with one of my courses

[@maitreking8693]

thanks for this clarification

[@ryanpower7704]

this video is excellent!

[@Taran72]

WOW! What a great video! thank you very much for making it.

[@omarbouzourraa9831]

excellent video! I like it

[@CJ_Pong]

I like this video. comprehensible , Thank you

[@Realdesirable.0w]

thanks for sharing!

[@electricalelectronicssolution]

Very amazing and helpful thank u.

[@ouarirou1884]

best explanation ever in short time

[@kamranb04]

It would be nice if you come up with the application part of this testing procedure, like measuring the thickness of the coating,evaluating heat treatment etc

[@MaterialsScience2000]

Answer to "It would be nice if you come up with the application part of this testing procedure, like measuring the thickness of the coating,evaluating heat treatment etc": Thanks for pointing out further (important) applications - it is simply too much for us for the time being.

[@thangbui5185]

This is pure gold

[@justcurious3048]

very informative . thank you

[@Yorumcu63]

Great info

[@eesa4013]

Danke. Das Video ist sehr gut 👍🏻

[@checkz4946]

Masterpiece 😍

[@sanwalkhan8052]

good description

[@psalm302]

Thank you

[@sayedhassanphysics8491]

Very interesting

[@ramachandranm8387]

Very super.

[@polloloci21]

Awesome

[@davidbarrioshurtado4937]

the best video

[@donnymontreano9235]

ok thank you!! now I know why the transformer is using a steel core with a certain saw position.

[@qzorn4440]

Geee, this is a supercalifragilisticexpialidocious video and i have relearned the eddy current thickness mearsurement. is the eddy current thickness gap signal linear on steel? thanks...:)

[@RaviTeja-dy8oi]

It's a great video but "what is frequency selection formula of a material?"

[@Dan153769]

ChatGPT brought me here ... thank you for the knowledge.

[@shoshohamad9324]

Very thanks ..i from egypt

[@pereira2542]

great video For test what was the voltage used and how many turns does the coil have?

[@MaterialsScience2000]

Answer to "For test what was the voltage used and how many turns does the coil have?" The voltage was 10 V, the number of the turns of the large coils was about 50 to 100.

[@pereira2542]

MaterialsScience2000 Many thanks you can tell me what inductance of the coils that were used in the demonstration? Very good this video congratulations! !!

[@jwills8606]

Take it from an EE guy. Damn good explanation; terse and tight.

[@ViceN53X]

Since I'm currently studying for the Aviation Maintanence degree, would I have to buy my own Eddy Current Tester kit or would the workshop provide one?

[@MaterialsScience2000]

Answer to "Since I'm currently studying for the Aviation Maintenance degree, would I have to buy my own Eddy Current Tester kit or would the workshop provide one?" For studying this degree, a "selfmade" solution within a project or something similar would be a reasonable option. But later in "real life" a professional EC Tester kit is much better.

[@HarshPatel-qd5ce]

What is gauge of this copper wire???? And what is length of this? How much voltage supply? And what is diameter of pipe

[@Amadeus8484]

So its like finding pathways by analyzing the reliability of magnetic fields?

[@sairithvik9133]

tnq

[@rohitshinde8145]

god bless you

[@lakhalnada9567]

What is the frequency of the alternative current that the coil needs in these experiments?

[@MaterialsScience2000]

Answer to "What is the frequency of the alternative current that the coil needs in these experiments?" The alternating current frequency is around 10 to 15 kHz.

[@993ak]

Why you have stopped making videos, we need more videos, more, more, more!

[@sharadjoshi8005]

Eddy current dependent or independent of original field?

[@kresimirbradvica51]

If the crack is smaller than the reciever coil would the lateral position of the crack inside the reciever coil mean more current drop than if the crack were in the center of the reciever coil?

[@MaterialsScience2000]

Answer to "If the crack is smaller than the reciever coil would the lateral position of the crack inside the reciever coil mean more current drop than if the crack were in the center of the reciever coil?": This is an important point. A crack that does not affect the eddy current path cannot be detected, regardless of the coil arrangement. Thus, cracks that are completely outside the eddy current path, completely inside the eddy current path, or exactly parallel to the eddy current lines cannot be detected. However, if the eddy current path is affected by the crack, the arrangement of the exciting and receiving coils plays an important role. So the answer to your question could be yes or no. Unfortunately, this is a complex issue.

[@kingdimitrieclips5125]

nice video. can eddy current be used for subsea pipes?

[@MaterialsScience2000]

Answer to "nice video. can eddy current be used for subsea pipes?": Underwater inspection has its general difficulties. Nevertheless, eddy current inspection also works under water.

[@grizzledwarveteran2321]

I have a question. If you get a copper tube, wrap copper wire around and hook it up to some output, and you drop a strong magnet through the tube, will the eddy currents turn on the output? Sorry if this question is kind of novice

[@MaterialsScience2000]

Answer to "I have a question. If you get a copper tube, wrap copper wire around and hook it up to some output, and you drop a strong magnet through the tube, will the eddy currents turn on the output? Sorry if this question is kind of novice" Yes, you will be able to measure a short-time voltage at the ends of your copper wire in the form of a single +/- wave (as long as the magnet doesn't tumble around). The copper wire should be wound closely together in the form of a compact coil (not a very long one). Imagine the middle part of the tube. When the magnet drops through the tube, the local magnetic field changes rapidly and induces and eddy current in the tube. This eddy current creates its own magnetic field that superimposes with the magnetic field of the passing-by magnet. The resulting magnetic field (correctly: change of flux) flows through the coil made from copper wire and induces a voltage there. Actually quite complex; the falling magnet is slowed down more or less depending on the set up.

[@grizzledwarveteran2321]

Ok thank you very much!

[@Eastdusty]

at 01:10, don’t forget that applying an alternating voltage is what creates an alternating current which will create an alternating magnetic field.

[@MaterialsScience2000]

Answer to "at 01:10, don’t forget that applying an alternating voltage is what creates an alternating current which will create an alternating magnetic field.": Perfectly explained, thanks!

[@710571514]

这个不错，线圈和LVDT差不多

[@vusumuzipatrickdlamini7950]

can u please make a video about Acoustic emission (AE)

[@MaterialsScience2000]

Answer to "can u please make a video about Acoustic emission (AE)" Thank you for the suggestion, but unfortunately we are no experts in this area. So probably no, sorry.

[@ishankulkarni207]

Best

[@bayucangak]

this content very awesome i'm trying to follow this video but i have a problem, when the coil contact to conductor nothing happen at my instrument can u help me

[@MaterialsScience2000]

Answer to "this content very awesome i'm trying to follow this video but i have a problem, when the coil contact to conductor nothing happen at my instrument can u help me": Did you use about 10 V and 10 kHz frequency for the excitation coil? The devices must be able to measure voltages and currents with this frequency.

[@fatimabadreddine8296]

I would like to know the wire diameter used, and the dimension of the core please

[@MaterialsScience2000]

Answer to "I would like to know the wire diameter used, and the dimension of the core please": For video demonstration purposes the wire diameter was around 0.3 mm, the core diameter of the coil around 50 respectively 20 mm, the number of turns 50 - 100. These data are actually rather uncritical, the method works nicely with other data as well.

[@darshandipalidilipdudhane1077]

Dear Sir, why we are set hole on 40 degree and 1volt for differential channel and why we are set absolute channel 0.1 volt at 40 degree for internal tube inspection by bobbin probe. Can you please explain it

[@MaterialsScience2000]

Sorry, I do not understand your question. Hole? 40 degree? I am at a loss ...

[@ilhamginar2336]

Your video was so fantastic , i learn a lot from that , but i still can't understand about the coil. Can you tell me how to make the coil please

[@MaterialsScience2000]

Answer to "Your video was so fantastic , i learn a lot from that , but i still can't understand about the coil. Can you tell me how to make the coil please": Thank you very much for the praise. As for the coils, they are very easy to make. You just take a lacquer insulated copper wire of about 0.2 mm diameter and wind it into a coil with about 20 to 100 turns. For very small diameters you don't need a bobbin, but for larger coil diameters you need a bobbin made of an electrical insulator; we used a transparent polymer material.

[@ilhamginar2336]

@@MaterialsScience2000 yesterday i practice make the eddy current test like that. But the current meter can't up when the coil entered the material test. I don't know what wrongs with that , can you tell me, maybe there are something which must be considered

[@MaterialsScience2000]

"yesterday i practice make the eddy current test like that. But the current meter can't up when the coil entered the material test. I don't know what wrongs with that , can you tell me, maybe there are something which must be considered": We had similar difficulties at the beginning and had to change many parameters: the frequency, the voltmeter, the ammeter, the material. I'm afraid it's too long to explain in detail, sorry.

[@gordoncampbell3058]

What was the wire gauge characteristics in this experiment?

[@MaterialsScience2000]

Answer to "What was the wire gauge characteristics in this Experiment? In our laboratory typically 50 to 100 turns, voltage 10 V, frequency 10 to 15 kHz.

[@gordoncampbell3058]

Hi, is it possible to run this experiment with a DC voltage source?

[@MaterialsScience2000]

Answer to "Hi, is it possible to run this experiment with a DC voltage source?": I am afraid no, in any case not in the classical eddy current testing procedure. You need the alternating magnetic field of the excitation coil to create an eddy current in the test piece, and an alternating magnetic field is only created by AC. However, there exists a very special method of nondestructive testing, where a ferromagnetic test piece is magnetised by a large coil using DC. Defects in the test piece lead to a magnetic flux flowing out of the test piece surface. This magnetic flux may be detected by a receiver coil, that moves fast enough over the test piece surface. This test method, however, is closer to the magnetic particle testing than to eddy current testing.

[@andredionicioalejandrocast6179]

How I do the coil (how many turn, caliber, diameter)?

[@MaterialsScience2000]

Answer to "How I do the coil (how many turn, caliber, diameter)?": This is quite a common question. You find the answers in the discussions below, please have a look.

[@pratapkumarmishra8297]

please also make videos on torsion and bending test and tensile test method for brittle materials. thank you

[@MaterialsScience2000]

Answer to "please also make videos on torsion and bending test and tensile test method for brittle materials. thank you": I keep it in mind, thanks.

[@niuthon]

Where can I find analog meters so big?

[@MaterialsScience2000]

Answer to "Where can I find analog meters so big?": There is quite a range of suppliers, an internet search under "analog demo multimeter" will be successful

[@niuthon]

Thanks, it worked. Can you tell me what are the dimensions and number of turns of the coils? I am trying to repeat your experiments, but the coil parameters seem crucial.

[@Raj-er8fc]

Why no voltage induced in receiver coil when there is no defect? there should be some voltage induced in receiver coil when there is no defect because if electromagnetic induction

[@MaterialsScience2000]

Answer to "Why no voltage induced in receiver coil when there is no defect? there should be some voltage induced in receiver coil when there is no defect because if electromagnetic induction": But yes, a voltage is induced in the receiver coils. However, the induced voltage is different with and without a defect.

[@wl9052]

why does the inductance become low when the core is added？shouldn't it be higher since u is higher.

[@MaterialsScience2000]

Answer to "why does the inductance become low when the core is added？shouldn't it be higher since u is higher.": It is because the eddy current inside the (intact) specimen (the ring, the core) is high. The high eddy current produces its own magnetic field which acts against the primary field. So altogether the excitation coil "feels" less inductivity and less counteracting voltage inside the excitation coil.

[@samagbeyicensus9389]

If someone wants to replace or attach a bulb with the current meter, the bulb should be how many volts...... thanks

[@MaterialsScience2000]

Answer to "If someone wants to replace or attach a bulb with the current meter, the bulb should be how many volts...... thanks": You could actually replace each of the measuring devices with light bulbs. However, this is not practical because, as you can see, the voltages are typically less than 1 V and the currents are much less than 100 mA. The voltage drop across the ammeter is very small, typically less than 100 mV.

[@kyusiv9026]

Why did you stop uploading videos?

[@MaterialsScience2000]

Answer to "Why did you stop uploading videos?" A fair question. Well, we've been pretty busy with other topics. But several new videos (about the tensile test, advanced level) are in the queue.

[@SuperDheepan]

will eddy detect 0.1mm hole in stainless steel tube of wall thickness 0.4mm

[@MaterialsScience2000]

Answer to "will eddy detect 0.1 mm hole in stainless steel tube of wall thickness 0.4 mm"? This is a real problem, but it should work under certain circumstances. It will not be possible to detect such a small hole with a large coil, as shown at the beginning of the video. But it should work with a very small coil, maybe an even smaller coil than the one shown towards the end of the video.

[@lakhalnada9567]

What kind of coil is he using?

[@MaterialsScience2000]

Answer to "What kind of coil is he using?" All the large coils in our laboratory are simple flat coils with about 50 to 100 windings made from insulated copper wire

[@lakhalnada9567]

:)

[@lakhalnada9567]

Thank you so much. :)MaterialsScience2000

[@MasAtnan]

How to make the coil ?

[@MaterialsScience2000]

Answer to the question "How to make the coil ?": The coils are very easy to make. You just take a lacquer insulated copper wire of about 0.2 mm diameter and wind it into a coil with about 20 to 100 turns. For very small diameters you don't need a bobbin, but for larger coil diameters a bobbin made of an electrical insulator is very helpful; we used a transparent polymer material.

[@MasAtnan]

what kind of transformer is used?

[@MaterialsScience2000]

Answer to "what kind of transformer is used?": We did not use a classic transformer, but only the coils.

[@raymiles691]

Electricians would benefit🎓