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 -
415 views
Technical Discussions
Jun
Jun
22:36 Mar-04-2018
Cannot get UT echo from

We have been having trouble getting UT signal from a 3 in thick coating on a large metal cyclinder. We used to be able to get the echo signal back from the metal at the center. Lately, we lost the echo. Is it possible that the rubber is not mixed well and there is too much scattering? What other factor can lead to the loss of the signal?

 
 Reply 
 
Phil Harper
Director, Tribosonics
Tribosonics Ltd, United Kingdom, Joined Feb 2004, 10

Phil Harper

Director, Tribosonics
Tribosonics Ltd,
United Kingdom,
Joined Feb 2004
10
08:27 Mar-05-2018
Re: Cannot get UT echo from
In Reply to Jun at 22:36 Mar-04-2018 (Opening).

Hi,

There could be a whole number of reasons why this occurs. If the material is highly attenuative (3" of polymer probably is) then you could loose your signal. Are you measuring at the same temperature? Have you done an optical inspection of the good coating and the bad coating? Is your UT equipment calibrated and performing to specification? Has the supplier changed the materials without telling you? Has the geometry changed? Is your coupling different? Have you tried a Pitch/Catch arrangement? Have you tried dropping the frequency to get back to a point where you get a signal?

Hopefully some of these questions might help.

Best Regards,

Phil

Founder and CEO of Tribosonics Ltd

 
 Reply 
 
Jun
Jun
15:15 Mar-05-2018
Re: Cannot get UT echo from
In Reply to Phil Harper at 08:27 Mar-05-2018 .

Phil,

We are not making any changes. We actually made a reference block 3"X5" in the lab and was able to get signal. But the production coating cannot get signal even on 1" thick sample sampled from the product while freestanding right next to the reference 5" block. We are suspecting microvoids from insufficient pressing while making the coating, or moisture?

 
 Reply 
 
Phil Harper
Director, Tribosonics
Tribosonics Ltd, United Kingdom, Joined Feb 2004, 10

Phil Harper

Director, Tribosonics
Tribosonics Ltd,
United Kingdom,
Joined Feb 2004
10
16:50 Mar-05-2018
Re: Cannot get UT echo from
In Reply to Jun at 15:15 Mar-05-2018 .

Hi,

Interesting. There is clearly something going on. Without knowing the materials or the processing method I don't know what is happening but clearly there is an effect. It is not uncommon for 'samples' to be made separately from the manufacturing process and therefore to be anything but a 'sample'. Really you need a sample (better, samples) from the actual production line with actual materials and manufacturing processes.

Phil

 
 Reply 
 
Simon Amallraja
Simon Amallraja
06:10 Mar-06-2018
Re: Cannot get UT echo from
In Reply to Jun at 22:36 Mar-04-2018 (Opening).

What do you want to test? Bond between the materials?

For such high thickness you need to use high power and high energy tone burst Ultrasonic Pulser Receiver. contact us for more info on that.

 
 Reply 
 

Product Spotlight

HARDNESS TESTER TKM-459CE combi

TKM-459CE combi applies 2 methods of hardness control: UCI and Leeb. It provides high-accuracy tes
...
ting of metals and alloys as well as items of different sizes and configurations, their hardened layers and galvanic coatings. Device represents results in HB, HRC, HV and others. Shock-, dust- and water-proof housing with intuitive software make this gauge easy to use in all working conditions.
>

PAUT Probes

Typical Phased Array probes have frequencies between 1MHz and 20MHz and the number of wafers is 10
...
to 128. M2 Electronics offers customers conventionally ultrasound probes and the ability to provide high-precision Phased Array Ultrasound Probes of up to 256 wafers. We can also customize the probe for our customers to meet the specific application requirements of the user.
>

Research and Application Development For NDT

Acuren’s Research and Application Development specializes in the development of advanced ultraso
...
nic inspection techniques and systems for challenging inspection applications, with an emphasis on practical solutions which are field deployable. Services include manual and automated ultrasonic inspection system development, inspection technique optimization using laboratory scale studies and ultrasonic modeling (CIVA, BeamTool), preparing technical justification for technique evaluation and qualification (Probability of Detection and sizing accuracy studies), inspection/calibration/analysis procedure preparation to support field deployment of custom techniques, and development of custom imaging algorithms to support challenging inspection applications.
>

FAAST-PA! OEM Patented phased Array for high speed UT inspection

Multiangle, Multifocus, Multifrequency, Multibeam. Instead of stacking UT electronics and having m
...
any PA probes, FAAST-PA is able to transmit all delay laws within ONE single shot in Real time.
>

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