Dead zone, near zone, far zone: Ultrasonic Testing Dead zone, near zone, far zone

[@xiaomiaoniu9183]

There might be an error, at 2:00. The second equation missed 'D'.

[@gustavofoss2280]

what does 6db mean? the sound loses power proportionally to the inverse of the distance squared, what does 6db mean exactly? 6db per cm? 6 db of what? it doesnt even make sense.

[@mustaphabenbihi]

Thanks for your comment. The 6dB drop is very famous method for defect evaluation in welding inspection. I've explained the method in details in my course on udemy. You can check out this animation learn more about it twi.phasexnde.com/home/tasters/ut-taster/dashboard/section-2-0-degree/chapter-8-evaluation/measuring/meaning-of-a-6db-drop/

[@barrbudo]

Gustavo, a 6dB increase means that sound pressure doubles, while a 6dB decrease means that it drops by 50%.

[@knaw35]

I am afraid that your Dead Zone explanation is not correct. Please, refer to other professional material and consider wedge (delay line) and no wedge cases.

[@barrbudo]

Interesting that you point this out. When I looked at the drawing, I was confused because what he called dead zone looks like the near field to me.

[@newsarabian]

good explanation, excellent job

[@mustaphabenbihi]

Thank you!

[@ThatGuy-vp3un]

What good explanation he is just reading the presentation without any elaboration. This sucks.

[@MegaLex77]

Dear Mustapha unfortunately your Ultrasonic Testing Course is not for free.

[@barrbudo]

Well, good things have their value, so consider the price of the course to be an investment :)