Twin Peaks - UT Root Signals

If you aren't old enough, Twin Peaks was a whacked out show around 1990 that started with a decent premise and then devolved into a slurry of confusion and "what the heck" moments.
Oh yeah, and this video is about UT stuff.

[@hugomarquez4199]

Thanks, great explanation 👍🏾

[@justinskillng5371]

When in doubt, plot it out.

[@gislia.gudmundsson9752]

Wow...very very good video Paul !!

[@hollowayndtengineeringinc.5201]

Thanks buddy!

[@rad9693]

Great content

[@gustavoporras5905]

Thank you Paul. Pure gold for me as an amateur in the matter. Please so a little question. That inspection is more of a free displacement where AScan provides the info to detect and confirm the tween peaks. But if I moving with a guide following a linear encoding and I depend also in what I see in the SScan what would you recommend? Thank you again.

[@hollowayndtengineeringinc.5201]

Hi Gustavo, I had a similar comment to yours so I will probably do another related video using phased array and how to identify the root signal. Using the extraction cursor on the Veo it is a breeze.

[@neilaneilaneila]

1 like for the Voivod T-shirt 😁

[@astarindia9487]

Superb Explanation as always!
Thank you!
As a tutor myself I find it sometimes difficult to explain this to the students, this video will help a lot. Only if you allow to use it.

[@phil107stein]

Great video again Paul. It’s me or the root-crown reflection is something absent in TFM. Is it a TLLT travel mode? I have to test this with my veo3 now…! It would be also nice to do TFMi from both sides and build up a nice root profile image. :)

[@hollowayndtengineeringinc.5201]

Good question! Now you have me thinking

[@barrbudo]

Philippe, what do you mean by "root-crown" reflection?

[@darrenmitchell1792]

Thanks

[@darrenmitchell1792]

Thanks

[@davidyang8550]

You are a Good Professional from south Korea.

[@hugogutierrez9898]

Increíble video gracias! Saludos desde colombia

[@Harry001989]

There is not too many good practical videos like yours.
I think its a big problem that during training there is not too many hours spent just on signal interpretation. How many kms of welds are cut because of root signal due to lack of experience :)

[@mattthrower8674]

Interesting, I had this twin peak signal whilst working on some 20" sch 80 I believe. Nobody knew what that were.
The near peak as you refer to it, would reach about 50% height whilst the far peak would remain in place.
Something didn't sit right so I asked the welder to flush the root off (easily accessible) and there it was, linear indication running along the root bead, didn't even need the magnet to see it.

[@hollowayndtengineeringinc.5201]

Beauty!!

[@Taco-no8wz]

So much help thank you !!

[@ricklauman2281]

Thank you Paul. You are the best NDT communicator!

[@salahmsilti1926]

Precious pulses coming from ultrasonic universe.thank you

[@javierravila5712]

This guy's is. A beast, good video man!

[@kevinmcgrath2077]

Seems overly complicated and difficult for newbies to grasp. What advantages does this technique have over a standard lateral scan, fixed at half skip, noting signals earlier than the root?

[@hollowayndtengineeringinc.5201]

It's not so much a technique as just a way to tell the difference.

[@lucianraducanu5376]

Great video! Thanks!
A question for "far side echo" - it may hide a "littlle problem" there (undercut, lack of fusion, tor crack) suprrimposed in position with expected far side echo. You recommend (right) to scan on the other side (which anyway should do if access...shouldn't?) ...but if the other side is not accessible--- is the weld root still to be considered "inspectable"?
I thought both sides scans should be a must. Should?!
Thanks for the videos you share!

[@hollowayndtengineeringinc.5201]

I believe most codes allow 1-side inspection (e.g. pipe to flange or elbow). But absolutely, if it is accessible then you should scan from both sides.

[@janboomstam1727]

But when you flip it on the other side and you don't get any signal, does it mean it's just a inregular root.

[@hollowayndtengineeringinc.5201]

Sometimes, yes. Hard to tell from opposite side unless you can definitely see something come up above the backwall

[@9600706761]

Plese Explain lamellar tear scanning for longitudinal and angle probe

[@hollowayndtengineeringinc.5201]

Great idea Kevin. I need a good sample. I've done this lots and it's definitely not easy.

[@joshm441]

Excellent video Paul!

[@tuskthiru2931]

Dear Sir
Mode conversion echo singnal and root signal will receive crystal or not receive crystal? please clarify me.

[@geemarino6066]

Thankyou nice video

[@QWERDF]

Thank's Paul.
I am working as a UT inspector in Korea.
It's a very helpful video.
My seniors teach me that if you know how to find the root signal, you'r half done. (Actually it seems really difficult...)
I found it every day imagining sound path but, it's amazing that there's a way to distinguish it like this. :)
Thank you for making a video about stainless steel pipe.

[@timothytraveller9044]

Thanks Paul, clear and complete explanation as always.

[@govindpilkhwal9179]

Hello sir, I recently started watching your videos and I like them, some of them I understand and some of them I don't because those are some high stuffs and my basics are not good, actually I have lot of doubts which I really want to clear but I don't get clear cut answers or I don't get convinced. I try to Google or search for videos but that don't help much. I need someone who can directly clear my doubts as I am working in this field and I want to do it correctly without doubts.
Please help me and let me know where I can reach you or ask you my doubts Directly and you can reply whenever you have time.
Thank you.

[@aerialrescuesolutions3277]

Take a class at Hellier Institute. Anaheim, California, and or Texas.

[@jeanfortin1290]

Now, no one can argue . Thank you so much Paul

[@davidlambert498]

thank you

[@hollowayndtengineeringinc.5201]

You are welcome