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 -

AT-Automation Technology GmbH
AT -Automation Technology is a systems house for industrial image processing. AT offers thermographic ndt systems as well as high-speed 3D sensors.
482 views
Technical Discussions
Binil
United Arab Emirates (UAE), Joined Oct 2018, 1

Binil

United Arab Emirates (UAE),
Joined Oct 2018
1
15:26 Apr-03-2020
Height sizing in Paut using 3 dB drop method using TRL technique

Can anyone explain the technical reason why 3 DB drop method will be more accurate than 6 DB for height sizing when using TRL technique (DMA) probe.

 
 Reply 
 
Anmol Birring
Consultant,
Birring NDE Center, Inc., USA, Joined Aug 2011, 805

Anmol Birring

Consultant,
Birring NDE Center, Inc.,
USA,
Joined Aug 2011
805
00:40 Apr-05-2020
Re: Height sizing in Paut using 3 dB drop method using TRL technique
In Reply to Binil at 15:26 Apr-03-2020 (Opening).

Answer is not that straight forward. Both have limitations.
My suggestion would be that you take measurement on known size reflectors to understand yourself.

 
 Reply 
 
Pramod Myakal
India, Joined Feb 2019, 9

Pramod Myakal

India,
Joined Feb 2019
9
19:13 Apr-05-2020
Re: Height sizing in Paut using 3 dB drop method using TRL technique
In Reply to Anmol Birring at 00:40 Apr-05-2020 .

Yes , I agree with, Mr. Anmol.

The best way is work on artificial notches / defects of known sizes. Study on even 6 db or 12db drop method , is different.

you can find several studies, done with several instruments, and probe combination.

It all depends on beam profile, mainly, and due to TRL have focus depth, hence it is determined highly the length of it, in material. Due to this limited length, it is not possible to use 6 or 12 DB drop method.

Self experiment with PA DAAH-DLA probes Sonatest Make for known size of LF sidewall and LF-Root, for length sizing, with 50mm focus, wedge, with 2.25 Mhz DAAH probes. on SS weld plate shows quite oversized while using 6 db, but where 3db shows quite a good co-ordination with the actual size.

https://sonatest.com/resources/application-notes/austenitic-stainless-steel-solution-daah-dual-linear-array-probe-1

please go through the above link.

Best Regards
Pramod Myakal
ASNT Level-III UT / ET / MFL

 
 Reply 
 
Vincent
R & D,
Vinçotte n.v., Belgium, Joined Mar 2001, 9

Vincent

R & D,
Vinçotte n.v.,
Belgium,
Joined Mar 2001
9
10:55 Apr-06-2020
Re: Height sizing in Paut using 3 dB drop method using TRL technique
In Reply to Binil at 15:26 Apr-03-2020 (Opening).

Hello,

this would also depend on the type of flaw you are looking for. Example: Stress corrosion cracking has a high potential to be undersized (with a 3dB sizing threshold) due to the high amplitude variation along the flaw. In this case one could use noise level sizing but this method will probably give oversizing on fatigue cracks.
If your procedure prescribes the 3 dB method, one may assume that there is a technical justification behind (or a qualification on representative blocks) and then you will find the answers in the qualification documentation.

 
 Reply 
 
Pramod Myakal
India, Joined Feb 2019, 9

Pramod Myakal

India,
Joined Feb 2019
9
14:08 Apr-06-2020
Re: Height sizing in Paut using 3 dB drop method using TRL technique
In Reply to Vincent at 10:55 Apr-06-2020 .

HI Vincent,
I agree your comments but for conventional or PA sizing, However feel restricted to do it with TRL probes or DLA / DMA probes for " STC / HTHA.

I feel the best is to carry out TFM, for proper sizing.

web article would be helpful as under.

https://sonatest.com/application/files/6715/2361/1353/Corrosion_Mapping_from_PA_to_TFM_Sonatest-APPS.pdf.pdf

Regards
Pramod

 
 Reply 
 
Anmol Birring
Consultant,
Birring NDE Center, Inc., USA, Joined Aug 2011, 805

Anmol Birring

Consultant,
Birring NDE Center, Inc.,
USA,
Joined Aug 2011
805
16:51 Apr-06-2020
Re: Height sizing in Paut using 3 dB drop method using TRL technique
In Reply to Binil at 15:26 Apr-03-2020 (Opening).

Some basics on 6 dB drop
Works well for sizing laminations with straight beam probe when the flaw size > probe size
For flaw size < probe size, you end up measuring beam spread

For height sizing other variables play role

 
 Reply 
 

Product Spotlight

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.
>

GEKKO, Standard and Advanced phased-array for Easier inspection

M2M Gekko® is a field-proven flaw detector offering PAUT, UT, TOFD and TFM through the streamline
...
d user interface Capture™. Released in 32:128, 64:64 or 64:128 channel configurations, Gekko combines high- resolution and speed while reducing inspectors’ training time.
>

New PHAsis module for longitudinal weld seam inspection

PHAsis® Phased Array manual ultrasonic spot weld inspection device is now ideally suited for test
...
ing of longitudinally welded seams (e.g. Arplas® seam, short line seams) with a length of 3 to 12 mm.
>

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.
>

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