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 -

642 views
Technical Discussions
David Harvey
Engineering
ATI - Wah Chang, USA, Joined Nov 2002, 42

David Harvey

Engineering
ATI - Wah Chang,
USA,
Joined Nov 2002
42
06:18 Apr-06-2005
Side lobes

I am looking for a good, rather basic (read: clear) discussion of the effect of the sound beam side lobes on performance of both contact and immersion tests. Is anyone aware of literature that addresses the subject, or that has wisdom to share?

Please respond to the message board, and not to my email address, since my company's spam filtering often filters messages from unfamiliar addresses.


 
 Reply 
 
Ed Ginzel
R & D, -
Materials Research Institute, Canada, Joined Nov 1998, 1307

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1307
05:51 Apr-07-2005
Re: Side lobes
David:
As for an easy read I suggest the new book by RD Tech on Introduction to Phased Array ULtrasonic Technology. There are a few related topics. But it makes little difference if the lobe is a grating lobe from a phased array probe or it is a lobe from a poorly backed single element unit or even a result of working in the near zone, the result is all about the same, i.e. an increase in pressure off-axis from the main beam (where you were expecting a continuous drop).

In line focused immersion probes we often see "horns" on either end of the beam when doing a plot of amplitude versus displacement across a calibration target like a small stainless steel ball.

When vertically sizing using the dB drop method we might see the effect in the vertical plane as a series of peaks as we move forward and back in a weld inspection. A small point reflector might be mistaken to be a multi-faceted flaw as a result.

It is all nicely covered in the book I referenced with images for illustration.
Ed

----------- Start Original Message -----------
: I am looking for a good, rather basic (read: clear) discussion of the effect of the sound beam side lobes on performance of both contact and immersion tests. Is anyone aware of literature that addresses the subject, or that has wisdom to share?
: Please respond to the message board, and not to my email address, since my company's spam filtering often filters messages from unfamiliar addresses.
------------ End Original Message ------------




 
 Reply 
 

Product Spotlight

Echomac® PA Tube Weld Tester

The new robotic Echomac® PA TW is an operator friendly test system for detecting weld zone defects
...
in tube and pipe caused by scarfing or welding processes. Electronic scanning ensures that the entire weld zone is covered without the need for mechanical movement or operator adjustment.
>

OPBOX with standard software is able to do all types of inspections and measurements: flaw detection in welds and materials, scanning of objects, testing composite materials, forged and moulded pieces, many UT inspections, measurements of properties of ma

Typical applications: UT measurements with pulse technique, Measurement of thicknesses also at hig
...
h temperatures, Measurements of properties of materials, including fluids and gases We are delivering a standard version of the software (for any Microsoft Windows up to 10 x64 with Microsoft Hardware certification report Approved) and for special needs: SDK with ready to use examples for LabView, MATLAB x64, C++ wrapper for dll, Python and Linux., and also low-level description of how to control our devices directly from any USB tools
>

Sci Aps Z-Series Portable Handheld Analysers

The world’s only handheld analyzer that measures carbon content in stainless (yes even L-grades),s
...
teels, and cast irons. Also accepted for low Si analysis for sulfidic corrosion analysis, and is widely used in the power industry for Cr analysis, for flow accelerated corrosion applications.
>

TraiNDE UT

TraiNDE UT is a virtual tool associated with a signal database which simulates real inspection con
...
ditions for numerous applications (Type A/V1 block, DAC block, welds and plates).
>

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