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 -
1573 views
Technical Discussions
Chris Coughlin
Chris Coughlin
01:06 Oct-18-2001
Dry-coupled UT transducers

Hi All;

TRI/Austin is looking for "dry coupled" ultrasonic transducers in the 1-5 MHz range that generate shear waves. Our application is a pretty tight fit, and ideally we're looking for fluid-filled wheels or similar configurations. Any and all help is appreciated; more info on the RFI is available from http://www.ntiac.com/rfi.html. Please note we're not interested in alternative NDE techniques or transducers (e.g. EMATs) at this stage.

Thanks!
Chris



 
 Reply 
 
Kelly Phelps
Consultant, IT Manager/Marketing Manager
NDT Engineering Corporation, USA, Joined Oct 2001, 6

Kelly Phelps

Consultant, IT Manager/Marketing Manager
NDT Engineering Corporation,
USA,
Joined Oct 2001
6
06:23 Nov-02-2001
Re: Dry-coupled UT transducers
: Hi All;
.
: TRI/Austin is looking for "dry coupled" ultrasonic transducers in the 1-5 MHz range that generate shear waves. Our application is a pretty tight fit, and ideally we're looking for fluid-filled wheels or similar configurations. Any and all help is appreciated; more info on the RFI is available from http://www.ntiac.com/rfi.html. Please note we're not interested in alternative NDE techniques or transducers (e.g. EMATs) at this stage.
.
: Thanks!
: Chris
.

Are you looking for dry-coupled roller probes? By what you describe this is what I am guessing.


 
 Reply 
 
Chris Coughlin
Chris Coughlin
06:55 Nov-02-2001
Re: Dry-coupled UT transducers
: : Hi All;
: .
: : TRI/Austin is looking for "dry coupled" ultrasonic transducers in the 1-5 MHz range that generate shear waves. Our application is a pretty tight fit, and ideally we're looking for fluid-filled wheels or similar configurations. Any and all help is appreciated; more info on the RFI is available from http://www.ntiac.com/rfi.html. Please note we're not interested in alternative NDE techniques or transducers (e.g. EMATs) at this stage.
: .
: : Thanks!
: : Chris
: .
.
: Are you looking for dry-coupled roller probes? By what you describe this is what I am guessing.
.


Yes, we're mainly interested in dry-coupled roller probes, but we haven't been able to find any yet that will support shear wave modes.


 
 Reply 
 
Ed Ginzel
R & D, -
Materials Research Institute, Canada, Joined Nov 1998, 1280

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1280
07:16 Nov-02-2001
Re: Dry-coupled UT transducers
: : : Hi All;
: : .
: : : TRI/Austin is looking for "dry coupled" ultrasonic transducers in the 1-5 MHz range that generate shear waves. Our application is a pretty tight fit, and ideally we're looking for fluid-filled wheels or similar configurations. Any and all help is appreciated; more info on the RFI is available from http://www.ntiac.com/rfi.html. Please note we're not interested in alternative NDE techniques or transducers (e.g. EMATs) at this stage.
: : .
: : : Thanks!
: : : Chris
: : .
: .
: : Are you looking for dry-coupled roller probes? By what you describe this is what I am guessing.
: .
.
:
: Yes, we're mainly interested in dry-coupled roller probes, but we haven't been able to find any yet that will support shear wave modes.
.
Do you REALLY mean that the dry-coupled roller must support Shear mode, as in SH shear wave inspection?
To accomplish this as a "coupling medium" you would still need a nonNewtonian viscous fluid to then couple the SH mode from the roller into the workpiece if using a piezo-element. Even with good SH shear coupling materials (like honey) you are likely to struggle to maintain a constant quality of coupling. It is hard enough to do this in a static condition let alone trying to do so on a dynamic scan.
I would think that most shear wave applications would use SV shear so you would rely on mode conversion from compression waves and the reverse (SV to compression) just as is done when using standard plastic refracting wedges.

Otherwise, if it is SH mode you require perhaps EMATs might be the only option.

Ed



 
 Reply 
 
Kelly Phelps
Consultant, IT Manager/Marketing Manager
NDT Engineering Corporation, USA, Joined Oct 2001, 6

Kelly Phelps

Consultant, IT Manager/Marketing Manager
NDT Engineering Corporation,
USA,
Joined Oct 2001
6
07:52 Nov-02-2001
Re: Dry-coupled UT transducers
: : : : Hi All;
: : : .
: : : : TRI/Austin is looking for "dry coupled" ultrasonic transducers in the 1-5 MHz range that generate shear waves. Our application is a pretty tight fit, and ideally we're looking for fluid-filled wheels or similar configurations. Any and all help is appreciated; more info on the RFI is available from http://www.ntiac.com/rfi.html. Please note we're not interested in alternative NDE techniques or transducers (e.g. EMATs) at this stage.
: : : .
: : : : Thanks!
: : : : Chris
: : : .
: : .
: : : Are you looking for dry-coupled roller probes? By what you describe this is what I am guessing.
: : .
: .
: :
: : Yes, we're mainly interested in dry-coupled roller probes, but we haven't been able to find any yet that will support shear wave modes.

The problem is that at a shear wave angle, both the thickness of the roller material and the dead air space that might be encountered at the point that the roller curves up off the surface of the part being inspected, would provide too much attenuation. However, a tractor wheel design that keeps the shear wave flat to the surface would work, provided that the rubber tracks are thin enough to transmit sound.


 
 Reply 
 
Chris Coughlin
Chris Coughlin
08:17 Nov-02-2001
Re: Dry-coupled UT transducers
: : : : : Hi All;
: : : : .
: : : : : TRI/Austin is looking for "dry coupled" ultrasonic transducers in the 1-5 MHz range that generate shear waves. Our application is a pretty tight fit, and ideally we're looking for fluid-filled wheels or similar configurations. Any and all help is appreciated; more info on the RFI is available from http://www.ntiac.com/rfi.html. Please note we're not interested in alternative NDE techniques or transducers (e.g. EMATs) at this stage.
: : : : .
: : : : : Thanks!
: : : : : Chris
: : : : .
: : : .
: : : : Are you looking for dry-coupled roller probes? By what you describe this is what I am guessing.
: : : .
: : .
: : :
: : : Yes, we're mainly interested in dry-coupled roller probes, but we haven't been able to find any yet that will support shear wave modes.
.
: The problem is that at a shear wave angle, both the thickness of the roller material and the dead air space that might be encountered at the point that the roller curves up off the surface of the part being inspected, would provide too much attenuation. However, a tractor wheel design that keeps the shear wave flat to the surface would work, provided that the rubber tracks are thin enough to transmit sound.
.


Right, that's pretty much the same conclusion we had come to for the transducers. We're hoping to find some COTS transducers, rather than (pun intended) reinvent the wheel.


 
 Reply 
 
Kelly Phelps
Consultant, IT Manager/Marketing Manager
NDT Engineering Corporation, USA, Joined Oct 2001, 6

Kelly Phelps

Consultant, IT Manager/Marketing Manager
NDT Engineering Corporation,
USA,
Joined Oct 2001
6
08:36 Nov-02-2001
Re: Dry-coupled UT transducers
: Right, that's pretty much the same conclusion we had come to for the transducers. We're hoping to find some COTS transducers, rather than (pun intended) reinvent the wheel.


It really wouldn't be hard to design since we already make several types of roller probes. The question is what you would use for the rubber track.



 
 Reply 
 
Ken Camplin
, Joined ,

Ken Camplin

,
Joined

00:39 Nov-02-2001
Re: Dry-coupled UT transducers
: : : : Hi All;
: : : .
: : : : TRI/Austin is looking for "dry coupled" ultrasonic transducers in the 1-5 MHz range that generate shear waves. Our application is a pretty tight fit, and ideally we're looking for fluid-filled wheels or similar configurations. Any and all help is appreciated; more info on the RFI is available from http://www.ntiac.com/rfi.html. Please note we're not interested in alternative NDE techniques or
transducers (e.g. EMATs) at this stage.
: : : .
: : : : Thanks!
: : : : Chris

: : : .
: : .
: : : Are you looking for dry-coupled roller probes? By what you describe this is what I am guessing.
: : .
: .
: :
: : Yes, we're mainly interested in dry-coupled roller probes, but we haven't been able to find any yet that will support shear wave modes.
: .
: Do you REALLY mean that the dry-coupled roller must support Shear mode, as in SH shear wave inspection?
: To accomplish this as a "coupling medium" you would still need a nonNewtonian viscous fluid to then couple the SH mode from the roller into the workpiece if using a piezo-element. Even with good SH shear coupling materials (like honey) you are likely to struggle to maintain a constant quality of coupling. It is hard enough to do this in a static condition let alone trying to do so on a dynamic scan.
: I would think that most shear wave applications would use SV shear so you would rely on mode conversion from compression waves and the reverse (SV to compression) just as is done when using standard plastic refracting wedges.
.
: Otherwise, if it is SH mode you require perhaps EMATs might be the only option.
.
: Ed
.
Hello Chris:

I know you orinally said you were not looking at EMATs, but I am sure you know that EMATs are particularly well suited for generating shear waves, especially SH waves. EMATs have come along way lately and have been fielded in very harsh enviroments and in automated fashion. If you would like to know more about our EMAT systems, please visit us at www.innerspec.com.


 
 Reply 
 

Product Spotlight

EKOSCAN Phased Array

In order to always fit your needs, EKOSCAN can manufacture any type of UT transducer, either convent
...
ional or Phased Array. As an ISO 9001: 2015 certified company, EKOSCAN is extremely careful as far a material selection and manufacturing processes are concerned. Our probes guarantee our customers the benefits of latest innovations regarding piezo-composite, backing, impedance adaptation layer, etc. Specific probes for hostile environment: high temperature, high pressure, corrosive environment,etc. Specific probes designed to fit your specific application: optimization of every parameter to guarantee you the best detection.
>

OmniScan™ X3 flaw detector

The OmniScan X3 flaw detector is a complete phased array toolbox. Powerful tools, like total focus
...
ing method (TFM) images and advanced visualization capabilities, enable you to complete your inspection with greater confidence.
>

NovaScope 6000

The all-digital Novascope 6000 is a portable, ultra-high precision thickness gauge for high-speed
...
thickness measurement. Novascope 6000 has unmatched capabilities and unique features including: •Superior Resolution with high contrast, high-speed color RF display •High pulser voltage •Real-time video output •Increased internal/external data storage •Programmable SetUp features •Battery & AC Powered
>

NDTkit RT

NDTkit RT, TESTIA's Digital Radiography software The NDTkit product line software for X-ray analysi
...
s. NDTkit RT is a software benefiting from the Ultis kernel which is dedicated to radiographic image analysis. It offers a set of tools and filtering processes to assist RT operators in finding relevant flaws.
>

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