Hi sir, this is with regards to the video that you had posted 6 months back, wherein you had demonstrated on how to size through wall height of a clustered porosity.My queries as you see below has been posted under the comment section of that video as well, but since its relatively an old video so possibly you may have missed out reading it because it was just posted yesterday. Here are my comments Is there a possibility that the technique that you just demonstrated to size the through wall height would give more accurate results in case of planar flaws as compared to such volumetric flaws? I noticed that there were a bunch of trailing signals of varying amplitudes (which was mentioned as broad signal envelope) as you were moving the probe back and forth towards the weld center line and also while orbiting. These signals are possibly coming in due to some mode converted signal set, for instance one component of the wave would have possibly hit the face of the flaw, there would have been some mode conversion to L-waves and after some reverberations L wave converting back to shear waves and back to the probe, so here the overall time of flight or the path taken by the waves would be longer giving rise to a bunch of trailing signals. Based on the geometry many such mode converted paths are possible. In the scenario as shown above there is a high possibility that while moving back and forth we are possibly hitting the same spot of the flaw but we are getting different depths possibly due to the change in path length or time of flight variation caused due to mode conversion. The through wall height measurements could possibly have some variations if you hit this same flaw from the other side of the weld due to some subtle changes in the geometry. Having said that sometimes we may get lucky that the through wall height measurements of such clustered porosity would tally quite well with the measurements as given by the manufacturer (Sonaspection, flaw tech, Ph tool etc.) but this may not happen always. If we take say about 5 to 6 samples of clustered porosity with some varying overall geometry, definitely there would be some samples where the overall through wall measurements wont tally with the measurements (based on radiography and which would be quite accurate for such volumetric flaws) as given by the manufacturer. The reason is purely due to the mode converted paths taken by the beam and which is very difficult to trace using a conventional single crystal approach. In order to accurately gauge the through wall height irregardless of the geometry we need to go on a tomographic approach where multiple mode converted paths are captured by the probe using an array of elements and each of this raw A-scans are evaluated for there individual time of flights. Please note a conventional phased array approach will also give similar results to the one as shown above. Lastly was this sample radio graphed?
Hello sir, thanks for your reply. Also i had posted some comments on your previously uploaded videos, I shall post them here again. Thanks a lot for uploading these videos, they are super informative. You are a fantastic teacher :) The explanation given in each of the videos is extremely crisp and clear and you indeed have some wonderful samples. I have circulated your video links to some of my pals who do UT testing and they really find it useful. Thanks for the effort and please keep posting such lovely and informative videos. Stay safe!
Are you done being retired? We need you to come back!
Hope you're living your best life, bud. Thank you for all of the help you've given us at CPCC.
Sir your teaching is very useful to us ....plz continue ...PAUT and TOFT
I would like to see you do a TCG cal with the sx
Thanks for share ...more information ...plz continue ....
Please upload more video in PAUT AND TOFT ....
WE WILL DEVELOP UR CHANNAL ...
Hello Sir,
Thanks for the uploads.
Do you have a "TKY" sample joint you can scan and upload too,
sir?
Thanks for that video.
Thank you for sharing Sir, really helpful and educational.
Hi sir, this is with regards to the video that you had posted 6 months back, wherein you had demonstrated on how to size through wall height of a clustered porosity.My queries as you see below has been posted under the comment section of that video as well, but since its relatively an old video so possibly you may have missed out reading it because it was just posted yesterday.
Here are my comments
Is there a possibility that the technique that you just demonstrated to size the through wall height would give
more accurate results in case of planar flaws as compared to such volumetric flaws?
I noticed that there were a bunch of trailing signals of varying amplitudes (which was mentioned as broad signal envelope) as you were
moving the probe back and forth towards the weld center line and also while orbiting. These signals are possibly coming in due to some mode
converted signal set, for instance one component of the wave would have possibly hit the face of the flaw, there would have been some mode
conversion to L-waves and after some reverberations L wave converting back to shear waves and back to the probe, so here the overall time of flight
or the path taken by the waves would be longer giving rise to a bunch of trailing signals. Based on the geometry many such mode converted paths are
possible. In the scenario as shown above there is a high possibility that while moving back and forth we are possibly hitting the same spot of the flaw
but we are getting different depths possibly due to the change in path length or time of flight variation caused due to mode conversion. The through wall
height measurements could possibly have some variations if you hit this same flaw from the other side of the weld due to some subtle changes in the
geometry. Having said that sometimes we may get lucky that the through wall height measurements of such clustered porosity would tally quite well
with the measurements as given by the manufacturer (Sonaspection, flaw tech, Ph tool etc.) but this may not happen always. If we take say about 5 to 6
samples of clustered porosity with some varying overall geometry, definitely there would be some samples where the overall through wall measurements
wont tally with the measurements (based on radiography and which would be quite accurate for such volumetric flaws) as given by the manufacturer.
The reason is purely due to the mode converted paths taken by the beam and which is very difficult to trace using a conventional single crystal approach. In order to
accurately gauge the through wall height irregardless of the geometry we need to go on a tomographic approach where multiple mode converted paths are captured by the probe using an array of elements and each of this raw A-scans are evaluated for there individual time of flights.
Please note a conventional phased array approach will also give similar results to the one as shown above.
Lastly was this sample radio graphed?
Hello Adi. Thank you for your input and observations. Every point you make is true and informative. This sample ways radiographed.
Hello sir, thanks for your reply. Also i had posted some comments on your previously uploaded videos,
I shall post them here again.
Thanks a lot for uploading these videos, they are super informative. You are a fantastic teacher :)
The explanation given in each of the videos is extremely crisp and clear and you indeed have some wonderful
samples. I have circulated your video links to some of my pals who do UT testing and they really find it useful.
Thanks for the effort and please keep posting such lovely and informative videos.
Stay safe!
Hi jonh
He is doing work calibration