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 -

Canadian Institute for NDE
We are specialized in training for Radiography, Ultrasonics, Magnetic Particle, Liquid Penetrant, Eddy Current and emerging NDT technologies.
1247 views
Technical Discussions
creed
NDT Inspector,
n.n., Joined Jul 2009, 33

creed

NDT Inspector,
n.n.,
Joined Jul 2009
33
04:48 Dec-06-2012
Eddy current testing for welds

Hi everyone,
I have quick questions related to Weld Eddy Current Tesing:
1. " When we use 100kHz probe, Can we detect subsurface defects within 2mm depth? because we used the calibration block with 2mm depth slot signal is reference level (eg. 80% of full screen)?
2. With the thin thickness of parent metal in weld testing will affect to the ECT signal? and How to control if YES?
Eg: the weld with the parent metal thickness is 2 or 3mm whilst we us ED slot calibration block with 5mm thick.
Thanks

 
 Reply 
 
John Hansen
Director, - Eddy Current Technology
ETher NDE Ltd, United Kingdom, Joined Oct 1999, 73

John Hansen

Director, - Eddy Current Technology
ETher NDE Ltd,
United Kingdom,
Joined Oct 1999
73
10:32 Dec-06-2012
Re: Eddy current testing for welds
In Reply to creed at 04:48 Dec-06-2012 (Opening).

1) At 100 kHz in Carbon Steel (Ferromagnetic) the Standard Depth of Penetration (aka skin depth) is about 0.03 mm. This means that as standard then eddy current can only be considered a surface method.

2) I think your question is now answered unless your material is non-magnetic.

All the best

John Hansen

1
 
 Reply 
 
Franlk Lund
R & D,
United Kingdom, Joined Apr 2005, 221

Franlk Lund

R & D,
United Kingdom,
Joined Apr 2005
221
11:45 Dec-06-2012
Re: Eddy current testing for welds
In Reply to creed at 04:48 Dec-06-2012 (Opening).

Creed,

1. The calibration slot starts from the inspection surface, so it gives a path for the interrogating current to penetrate into the test block by going down and up the flanks of the slot. If your slot is on the other side of the block, then the interrogating current in the slotless surface is not interrupted and will not see the slot.

2. Things get different when your 2mm deep vertical slot penetrates to the other side of the 2mm thick test piece. Of course, a slanted defect can have a 2mm pocket depth without penetrating a 2mm thick plate.

Cheers,
Frank

 
 Reply 
 
creed
NDT Inspector,
n.n., Joined Jul 2009, 33

creed

NDT Inspector,
n.n.,
Joined Jul 2009
33
22:41 Dec-06-2012
Re: Eddy current testing for welds
In Reply to John Hansen at 10:32 Dec-06-2012 .

Thanks John and Franlk.
Your answers make me feel open-minded. Prior I had stupid perpective in checking thin material might affected to signal.
Cheers.

 
 Reply 
 

Product Spotlight

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.
>

TESTD-PT SYSTEM

Pulse thermography is a non-contact test method that is ideal for the characterization of thin fil
...
ms and coatings or the detection of defects. With a remarquable short test time and a high detection sensitivity, the Telops TESTD-PT is the perfect tool for non- destructive testing. With such high frame rates, it is even possible to investigate highly conductive or diffusive materials.
>

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.
>

High-performance Linear Phased Array Probes

Available to order from stock in a range of 5MHz – 7.5MHz and from 16 to 64 elements. Designed w
...
ith piezo-composite elements, Phoenix phased array probes provide high-resolution imaging to maximise sensitivity; accurate ultrasonic detection and sizing of defects in welds; and effective corrosion mapping. Housed in a rugged stainless steel case for on-site industrial NDT applications.
>

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