Sizing with Tip Diffraction

It's one-sided TOFD, that's exactly what it is.

[@mindaugasvaiciunas8488]

Would be interesting to see tip diffraction on cracks lying at an angle.

[@425749]

very good explanation

[@debasishroy638]

Looks really nice with the 10 MHz probe 😃

[@splocal]

Great content, it’s been almost 15 years since I played with tip diffraction. I remember calibrating and measuring the distance between the corner trap signal and tip diffracted signal. It seems though you are measuring TOF or from the initial pulse just like you would for and standard shear waves or compression wave testing? We didn’t have PAUT in those days to pick any angle. We used fixed high angle L-waves most often.

[@jacksonbowen867]

Hi Paul, how do you size something assuming it’s in the centre of your weld? This example you just get the top of the indication and subtract from the plate thickness. Do you get a tip diffracted signal from both the top and bottom of the indication? Also do you have any tips for identifying the tip diffracted signal for conventional UT? Thanks

[@hollowayndtengineeringinc.5201]

So yeah, a centreline crack or a sidewall lack of fusion. In my latest video I show a SWLOF sizing with the top and bottom diffracted signals. With PAUT it's just so much easier because you see everything all at once. In 2024 here (actually, since the early 2000's) we've been spoiled with PAUT. There are many out there that are so much better than I am at characterization and sizing with conventional. It's trickier and might require switching wedges. But no one should be shamed for using a better tool. Sure, the people that built houses with homemade nails should be commended for their ingenuity. But that doesn't make houses built in 1880 better than today's contruction with modern tools and screws.

[@jacksonbowen867]

@@hollowayndtengineeringinc.5201 hahahah I agree! Thankyou!

[@andresdelcastillodubuc702]

Always great content! Thanks!

[@martinblazej1430]

Hi, I want to ask you. I think about some machine for me. But Olympus is so much expensive, Karl deutsche is same. So I maybe think you sonatest is maybe good. Can you give my some opinion. Thanks Martin and thanks for your videos. Is great job!!! Thanks 👍

[@hollowayndtengineeringinc.5201]

Olympus, Sonatest, Zetec, Eddyfi, GE... they are all good machines. There isn't one that is better than the others at everything, only a machine that is "best for you".

[@santiagocruz9060]

Very clear