where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -
525 views
Technical Discussions
Massimiliano Pau
Teacher, -
Univ. of Cagliari, Dept. of Mechanical Engineering, Italy, Joined Sep 2002, 25

Massimiliano Pau

Teacher, -
Univ. of Cagliari, Dept. of Mechanical Engineering,
Italy,
Joined Sep 2002
25
03:09 Jan-29-2002
Diffraction effects

Dear colleagues

I'm trying to measure small flat-bottom holes (diameters from 0.5 to 10 mm) in a steel specimen by scanning them with a longitudinal immersion 10 MHz focussed probe.

My question are:

1. How diffraction effects can alter the reflection of the ultrasonic beam when part of it hits the edge of the hole?

2. Can I take into account these effects in order to "correct" the size which comes from the C-scan results?

3. Is there any literature reference (please not too theoretical if possible) on this topic?

Thanks in advance

Massimiliano Pau

P.S. thanks to Joe Buckley for his precious advice about the noise with electromagnetic fields generated by an inverter. It worked!




 
 Reply 
 
N.T. Azarov
Engineering
GosNIIGA, Russia, Joined Jan 2000, 12

N.T. Azarov

Engineering
GosNIIGA,
Russia,
Joined Jan 2000
12
09:21 Jan-31-2002
Re: Diffraction effects
-----éÓÈÏÄÎÏÅ ÓÏÏÂÝÅÎÉÅ-----
ïÔ: forum@ndt.net
ëÏÍÕ: undisclosed-recipients:;
äÁÔÁ: 29 ÑÎ×ÁÒÑ 2002 Ç. 15:13
ôÅÍÁ: Diffraction effects

> * This article was posted by Massimiliano Pau
>Reply at:http://www.ndt.net/wshop/forum/messages/3839.htm
>
>Dear colleagues
>
>I'm trying to measure small flat-bottom holes (diameters from 0.5 to 10 mm)
in a steel specimen by scanning them with a longitudinal immersion 10 MHz
focussed probe.
>
>My question are:
>
>1. How diffraction effects can alter the reflection of the ultrasonic beam
when part of it hits the edge of the hole?
>
>2. Can I take into account these effects in order to "correct" the size
which comes from the C-scan results?
>
>3. Is there any literature reference (please not too theoretical if
possible) on this topic?
>
>Thanks in advance
>
>Massimiliano Pau
>
>P.S. thanks to Joe Buckley for his precious advice about the noise with
electromagnetic fields generated by an inverter. It worked!
>

>Dear, Mr Pau.
I have experience of a ultrasonic control thin-walled (0,5-5mm) of welded
seams on frequencies 10-15MHz by a focusing transducer (immersion control).
A diameter of a focal spot 0,5mm. C-scan the image of an imperfection (flaw)
is a convolution of two functions: functions of reflection of an
imperfection (flaw) (including diffractional effects) and cut of a focal
spot. The dependence of sort is obtained: "conditional square - diameter of
an imperfection (flaw)".
My E-mail:
azar@orc.ru, azar@ncplg.msk.ru
N. Azarov.
>--
.



 
 Reply 
 

Product Spotlight

Robotic laser shearography enables 100% inspection of complex, flight-critical composite structures

An article in “Composites World Magazine” showcases Non Destructive Testing of aero-structures
...
with Laser Shearography. Over the years Dantec Dynamics has supplied many solutions for the aerospace industry. Referring to specific customer projects several of these cases are examined to outline the advantages of using Laser Shearography for automated defect detection.
>

PROlineTOP Plug & Play Ultrasonic inspection device

As Plug & Play solution it units all control and operation elements in a small housing and therefo
...
re replaces the typical control cabinet...
>

Aerospace Systems - Automated Ultrasonic Inspection

USL are specialists in the design and manufacture of turnkey ultrasonic inspection systems for aer
...
ospace applications. From monolithic composites to complex honeycomb structures. This video shows just a few examples of what is possible, find out more at: www.ultrasonic-sciences.co.uk
>

iProbe - USB Phased Array Probe

Turn your PC, Laptop or Tablet into a powerful 32:64 Phased Array system with our USB powered Phas
...
ed Array iProbe and inspection software package. Perform affordable weld inspection and corrosion mapping inspections with this powerful but small system. The probe has a 100V pulser, 8K PRF, dual axis encoder input and achieves outstanding signal quality.
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window