in 1:12, why the path of echo 2 doesn't or why isn't there an echo follows this way: initial pulse-> reflect from the bottom -> pass through the interface between coating& part -> reflect from the top surface of the coating -> back into the object, reflect from the bottom of the part, received by the transducer?
It does, it's just that it's so closely spaced because the coating thickness is thin, you can't resolve it. First one back wins, and that's the at the coating to part interface.
Correct said in the end. We are using echo to echo,sometimes is not working due to corrosion or heavy coating also it's not working,and what is difficulty using TR probe plz explain
Using trigonometry, you can calculate where your root signal should come up. Go onto the piece and check how close theory is to real life. Any signal that shows up before the distance that you have empirically determined is an indication. That is just my method and there can be others that are better. Keep up the search!
hello Paul, first and foremost thank you for always sharing such useful content, I have seen that this doesn't usually apply when you measuring through metallic coating, e.i: hot dipped galvanised materials, any tips on that? cheers
Hi Michael, thats "coating + thickness (down to bottom) + thickness (back to top)". Then it reflects off the steel-coating interface and turns around and goes into the orange text "thickness (down to bottom) + thickness (back to top) + coating (back to transducer)".
Awesome video. Did you do a video on dual through paint thickness
Not with a dual... I think you're referring to the thru-coat type of transducer. Cool idea, I have one of those. I'll add it to the list!
@@hollowayndtengineeringinc.5201 yes I meant thru coat
thank you paul, i gain knowledge from your explanation, will try to do hand on with my veo+
Loving your videos Pual so well made.
Thanks buddy!
Excellent... please please make video on RF,HALF AND FULL rectify mode and it's uses.
On my list!
in 1:12, why the path of echo 2 doesn't or why isn't there an echo follows this way: initial pulse-> reflect from the bottom -> pass through the interface between coating& part -> reflect from the top surface of the coating -> back into the object, reflect from the bottom of the part, received by the transducer?
It does, it's just that it's so closely spaced because the coating thickness is thin, you can't resolve it. First one back wins, and that's the at the coating to part interface.
Is it the difference of acoustic impedance between the coating and the part that causes the first one to dominate?
Correct said in the end. We are using echo to echo,sometimes is not working due to corrosion or heavy coating also it's not working,and what is difficulty using TR probe plz explain
How to tell the difference between a root indication and a normal root signature,
Using trigonometry, you can calculate where your root signal should come up. Go onto the piece and check how close theory is to real life. Any signal that shows up before the distance that you have empirically determined is an indication. That is just my method and there can be others that are better. Keep up the search!
great video!
Very useful, thank you.
Really nice
Paul, can you link the article?
www.hollowayndt.com/news/2018/10/22/an-explanation-of-the-echo-to-echo-measurement-technique
really cool man. thank you!
have a good day
Well done! More please
Is it wrong if You measure between first and second echoes
This is the point of the video, that measuring between consecutive echoes is the *only* way if you want to remove the effects of coating.
@@hollowayndtengineeringinc.5201 ok, I just was wondering, is the same if its first and second or second and thirt echoe. thanks for the video
It is very interesting, thank you. But, what about both sides of the material with coating?
That would be interesting to try
Borth sides coated doesn’t change the echo-to-echo reading. You might get a small peak behind the true backwall echos.
Thanks sir . Dac and tcg technic??
great help! I look forward to more videos!
do you just use sonatest? or other systems like GE, Olympus?
I have used Olympus a lot. Relatively new to Sonatest. Thanks for the comment!
How can one deduce the coating thickness percentage that is to be be dismissed as the probe’s dead zone?
The dead zone extends the duration of the waveform, but does not affect the leading edge.
Could you please speak about eddy current system
Thank you
Holy crap I love NDT.
hello Paul, first and foremost thank you for always sharing such useful content, I have seen that this doesn't usually apply when you measuring through metallic coating, e.i: hot dipped galvanised materials, any tips on that?
cheers
Awesome!!
Does your UT unit have a TOF function?
Hi, where does that (c+t+t) come from at the beginning of the second echo signal. Shouldn’t it be (c+t)?
Hi Michael, thats "coating + thickness (down to bottom) + thickness (back to top)". Then it reflects off the steel-coating interface and turns around and goes into the orange text "thickness (down to bottom) + thickness (back to top) + coating (back to transducer)".
👍
Awesomeee
Interesting
Hi dear Poul. / to / or ^ to ^, could you show the difference, in some next opportunity
I did a video on gate modes, check it out