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 -
577 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, 1266

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1266
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

Panther

M2M PANTHER is a phased-array equipment designed for both desktop and industrial applications, offer
...
ing unparalleled performance in a compact unit. It combines the speed required for industrial integrated Phased-Array Ultrasound (PAUT) solutions, with the most complete set of total focusing method (TFM) imaging techniques, making it the ultimate tool for R&D and procedure qualification.
>

Ultrasonic tomograph for imaging of concrete structures А1040 MIRA

Applicable for concrete inspection allowing imaging of the internal structure of objects from conc
...
rete, reinforced concrete, different stones. The operation applies pulse-echo technique at one-side access to the object. The instrument is feasible for concrete inspection for searching conduct ducts, conduits, detection of foreign inclusions, holes, honeycombing, cracks and other concrete defects.
>

Semi-Automated Phased Array Immersion System for Small Composite Parts

Turn-key semi-automated system as an improved and affordable solution for inspection of small comp
...
osite parts. Includes support table, immersion tank, scanner, PA instrument, PC, Analysis software, database, wedge management and other options.
>

FlexoFORM™

The FlexoFORM™ solution integrates flexible phased array probe technology in a scanner to solv
...
e the challenges that come with inspecting pipe elbows. When combined with a water column, this solution can be used to collect easy-to-interpret data on elbows with diameters ranging from 4.5 in. OD up to flat and offers many benefits.
>

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