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 -

Materials Research Institute
Consulting to the NDT industry.
687 views
Technical Discussions
simone brocco
Student
university, Italy, Joined Jul 2000, 4

simone brocco

Student
university,
Italy,
Joined Jul 2000
4
03:30 Jul-23-2000
medical ultrasonic probe

I'm looking for some works on influence of the thickness of a backing on the response of transducers".
Could you help me to find it ?



 
 Reply 
 
Dipl.-Ing. Martin Heinz
Dipl.-Ing. Martin Heinz
09:34 Jul-24-2000
Re: medical ultrasonic probe
: I'm looking for some works on influence of the thickness of a backing on the response of transducers".
: Could you help me to find it ?
:
The backing material consists normally of an resin and filler materials for damping sound and for increasing the acoustical impedance of
the backing. Increasing acoustic impedance means increasing density (weight) (e.g. by putting tungsten into the backing) and increasing
the speed of sound (e.g. by putting aluminia oxide into the backing). Of further interest there is the diameter of the grain of these filler
materials, which should be in a certain dimension to the wavelength of the sound. If the acoustic impedance does not match as close as
possible to the acoustic impedance of the piezoceramic, only few sound energy can travel into the backing for beeing damped/destructed
into the backing. The most of the sound energy would be reflected several times between backing and piezoceramic and would produce
additional resonances. In this case an increasing of the thickness of the backing would not increase much the damping of sound. If the
backing is matched sufficiently to the piezoceramic, you can increase the damping by increasing the backing thickness in a certain range.
Increasing the damping of the sound means decreasing the quality of this "oscillator" and thus increasing bandwidth.
In the analysis of materials you sended it seems not so as some tungsten or aluminia oxide would be in this backing. I think they use Pb
for increasing the density / weight and thus increasing the acoustic impedance of their backing, because tungsten is much more
expensive than Pb.

Best regards,

Martin Heinz.



 
 Reply 
 
Michael Trinidad
Consultant,
LMATS Pty Ltd , Australia, Joined Jan 2003, 138

Michael Trinidad

Consultant,
LMATS Pty Ltd ,
Australia,
Joined Jan 2003
138
03:44 Jul-26-2000
Re: medical ultrasonic probe
: I'm looking for some works on influence of the thickness of a backing on the response of transducers".
: Could you help me to find it ?
:
I found a manufaturer's web site with a lot of information which is attached below. Maybe it can be of some use to you or they may be able to answer more specific questions.

Kindest Regards

Michael Trinidad




 
 Reply 
 
david linzer
david linzer
07:02 Sep-20-2001
your question
: I'm looking for some works on influence of the thickness of a backing on the response of transducers".
: Could you help me to find it ?
: it would be depending on the accuracy of the application as well as the range. ie the lower the range of the transducer the more sensitive it would be for atm flactuations (it would be sensitive to noise), but even though the influence can be checked by using both transducer (equivalent) and isolate the "backing" of only one of them, and than try to measure for the same input....
hope it helps




 
 Reply 
 

Product Spotlight

YXLON Cougar EVO

Scalable small footprint X-ray inspection systems for assembly and laboratory applications. The
...
YXLON Cougar EVO series was designed to provide the "best-in- class" inspection solutions for SMT, semiconductor, and laboratory assembly applications, while maintaining a small system footprint for maximum convenience. With optimized software and hardware, these systems produce higher quality and more consistent results than other electronics inspection systems currently on the market.
>

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...
>

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