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.

814 views
Career Discussions
Ed Ginzel
R & D, -
Materials Research Institute, Canada, Joined Nov 1998, 1261

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1261
09:52 Jul-20-2005
Phased Array S-scans Promo

This is posted as an item for discussion. Having seen the hyperbole surrounding what I think is a valuable tool, (phased arrays) I am a bit concerned that Great Expectations are being stirred that are unfounded in science and practical application.

Phased array technology has been around since the 1950s but only lately has it been popularised in NDT. This popularity is probably due to the reduction in price and size of equipment. It has a variety of options, many of which duplicate multi-probe or multi-axis encoded systems. But the unique aspect of phased array systems seems to derive from the sectorial scan (also called the azimuthal or S-scan).

However, other than as a propmotional "gimmick" can anyone explain why some of the marketing images use a true-depth sectorial (S-scan) display that indicates capabilities far beyond reasonable expectations?
I just received my copy of the BINDT Insight where the front cover image is of a UT operator putatively working on a weld inspection with such an S-scan display. But the display shows an angular sweep from 0° to about 80°! Not only is it unlikely that any phased array probe (even on a wedge) has such capability for weld inspection, the fact that the sweep passes from 0° through 33° means the test is using nearly half of the sweep data from below the first critical angle. This would be virtually impossible for the UT operator to make sense of!

Flaw position is incorrectly plotted when the S-scan is so configured! e.g. A velocity is typically programmed into the system so as to correctly display flaw depth with respect to angle. Only one velocity can apply so, assuming Shear wave velocity was used, the focal producing the 30° shear wave will also produce a compression wave around 67° (in steel). But any flaw detected by the 67° compression wave will be ploted as if detected early along the 30° path.

AC Whittle wrote an article in the Nov. 2004 Insight questioning if phased arrays were a Pancea or a Gimmick. I suspect they are neither, but if unreasonable expectations are set by marketing gimmicks they may suffer in the long run.

Ed



    
 
 Reply 
 
Joe Buckley
Consultant, ASNT L-III, Honorary Secretary of BINDT
Level X NDT, BINDT, United Kingdom, Joined Oct 1999, 520

Joe Buckley

Consultant, ASNT L-III, Honorary Secretary of BINDT
Level X NDT, BINDT,
United Kingdom,
Joined Oct 1999
520
01:30 Jul-22-2005
Re: Phased Array S-scans Promo

As one of those responsible for selecting this particular picture for the Insight front cover I suppose I had better respond to Ed's comment with some explanation.

Firstly let me state that there is nothing much 'marketingy' about the image, its a photo taken by the customer of a real operator working on a real weld on a real tower, soon to be installed somewhere in North America.

Of course Ed's points are valid, and no interpretation should be made of indications outside the range of around 35- 75 "onscreen" degrees.

However:

This is a manual test, If anything outside this shows up the probe can easily be moved so it is in the 'valid' region for investigation.

A series of repeat backwall echoes can be seen down the left hand side of the screen. This provides a check for any unexpected thickness change delaminations, or loss of coupling. Of course the indicated position will not be correct as these are compression wave and the screen is calibrated for shear velocity.

I would certainly not promote Phased array as 'you get a picture - thats whats in the metal' But these are experienced operators who know what they are looking at. They take the view 'why have a black area of screen when you can show something that might be useful'

In general I would agree with Ed's view, and particularly his recommendation of Alison's paper (which I just reread) For the right applications Phased array equipment has huge potential advantages, both technically and financially. As equipment vendors we are well aware of the problems that can be caused by unreasonable expectations, and we certainly have no intention to raise them.

For anyone wondering what this is all about I've posted a copy of the picture on
http://www.joe.buckley.net/images/P5120037(Medium).JPG


Joe Buckley

----------- Start Original Message -----------
: This is posted as an item for discussion. Having seen the hyperbole surrounding what I think is a valuable tool, (phased arrays) I am a bit concerned that Great Expectations are being stirred that are unfounded in science and practical application.
: Phased array technology has been around since the 1950s but only lately has it been popularised in NDT. This popularity is probably due to the reduction in price and size of equipment. It has a variety of options, many of which duplicate multi-probe or multi-axis encoded systems. But the unique aspect of phased array systems seems to derive from the sectorial scan (also called the azimuthal or S-scan).
: However, other than as a propmotional "gimmick" can anyone explain why some of the marketing images use a true-depth sectorial (S-scan) display that indicates capabilities far beyond reasonable expectations?
: I just received my copy of the BINDT Insight where the front cover image is of a UT operator putatively working on a weld inspection with such an S-scan display. But the display shows an angular sweep from 0° to about 80°! Not only is it unlikely that any phased array probe (even on a wedge) has such capability for weld inspection, the fact that the sweep passes from 0° through 33° means the test is using nearly half of the sweep data from below the first critical angle. This would be virtually impossible for the UT operator to make sense of!
: Flaw position is incorrectly plotted when the S-scan is so configured! e.g. A velocity is typically programmed into the system so as to correctly display flaw depth with respect to angle. Only one velocity can apply so, assuming Shear wave velocity was used, the focal producing the 30° shear wave will also produce a compression wave around 67° (in steel). But any flaw detected by the 67° compression wave will be ploted as if detected early along the 30° path.
: AC Whittle wrote an article in the Nov. 2004 Insight questioning if phased arrays were a Pancea or a Gimmick. I suspect they are neither, but if unreasonable expectations are set by marketing gimmicks they may suffer in the long run.
: Ed
------------ End Original Message ------------




    
 
 Reply 
 
François Mainguy
François Mainguy
03:36 Jul-24-2005
Re: Phased Array S-scans Promo
Bonjour - I was the project leader for the solution at Hitachi. I chose Mr.Jonathan Buttram (Level III, Interwav) to write the AWS procedure. He made pretty clear in the procedure that data displayed from 0 to 35 deg. are not to be used for measurements. They should be used for detection only, for laminar defects only. Any rigorous technician with proper Level I or II background will know how to use this carefully.

Unfortunately, other manufacturers of phased aray sold it with a "does-it-all-black-magic" étiquette, which annoyed the market, and this reactivity and Whittle's article are a proof of it.

HARFANG sales pitch always starts with "This is not magic, this is normal ultrasonics." We are active promoters of ethical information disclosure on phased array.

François Mainguy
Founder and VP-Technology
HARFANG Microtechniques inc. (Québec)

----------- Start Original Message -----------
: As one of those responsible for selecting this particular picture for the Insight front cover I suppose I had better respond to Ed's comment with some explanation.
: Firstly let me state that there is nothing much 'marketingy' about the image, its a photo taken by the customer of a real operator working on a real weld on a real tower, soon to be installed somewhere in North America.
: Of course Ed's points are valid, and no interpretation should be made of indications outside the range of around 35- 75 "onscreen" degrees.
: However:
: This is a manual test, If anything outside this shows up the probe can easily be moved so it is in the 'valid' region for investigation.
: A series of repeat backwall echoes can be seen down the left hand side of the screen. This provides a check for any unexpected thickness change delaminations, or loss of coupling. Of course the indicated position will not be correct as these are compression wave and the screen is calibrated for shear velocity.
: I would certainly not promote Phased array as 'you get a picture - thats whats in the metal' But these are experienced operators who know what they are looking at. They take the view 'why have a black area of screen when you can show something that might be useful'
: In general I would agree with Ed's view, and particularly his recommendation of Alison's paper (which I just reread) For the right applications Phased array equipment has huge potential advantages, both technically and financially. As equipment vendors we are well aware of the problems that can be caused by unreasonable expectations, and we certainly have no intention to raise them.
: For anyone wondering what this is all about I've posted a copy of the picture on
: http://www.joe.buckley.net/images/P5120037(Medium).JPG
:
: Joe Buckley
: : This is posted as an item for discussion. Having seen the hyperbole surrounding what I think is a valuable tool, (phased arrays) I am a bit concerned that Great Expectations are being stirred that are unfounded in science and practical application.
: : Phased array technology has been around since the 1950s but only lately has it been popularised in NDT. This popularity is probably due to the reduction in price and size of equipment. It has a variety of options, many of which duplicate multi-probe or multi-axis encoded systems. But the unique aspect of phased array systems seems to derive from the sectorial scan (also called the azimuthal or S-scan).
: : However, other than as a propmotional "gimmick" can anyone explain why some of the marketing images use a true-depth sectorial (S-scan) display that indicates capabilities far beyond reasonable expectations?
: : I just received my copy of the BINDT Insight where the front cover image is of a UT operator putatively working on a weld inspection with such an S-scan display. But the display shows an angular sweep from 0° to about 80°! Not only is it unlikely that any phased array probe (even on a wedge) has such capability for weld inspection, the fact that the sweep passes from 0° through 33° means the test is using nearly half ofthe sweep data from below the first critical angle. This would be virtually impossible for the UT operator to make sense of!
: : Flaw position is incorrectly plotted when the S-scan is so configured! e.g. A velocity is typically programmed into the system so as to correctly display flaw depth with respect to angle. Only one velocity can apply so, assuming Shear wave velocity was used, the focal producing the 30° shear wave will also produce a compression wave around 67° (in steel). But any flaw detected by the 67° compression wave will be ploted as if detected early along the 30° path.
: : AC Whittle wrote an article in the Nov. 2004 Insight questioning if phased arrays were a Pancea or a Gimmick. I suspect they are neither, but if unreasonable expectations are set by marketing gimmicks they may suffer in the long run.
: : Ed
------------ End Original Message ------------




    
 
 Reply 
 

Product Spotlight

NEW! The PragmaPro Instrument Platform

The PragmaPro is based on a modular cartridge technology and supports various NDT instrument modal
...
ities such as UT, PAUT, ECT and many more. This new platform is based on a machined, powder-coated aluminum frame for shock-proofness, best sealing qualities and maximum heat dissipation. This is practical to extend the outdoor temperature range and/or to extend the power injected in the transducers. The PragmaPro is aiming at a very wide range of applications, such as weld scanning, corrosion mapping and composite testing.
>

UCI Hardness Tester NOVOTEST T-U2

UCI hardness tester NOVOTEST T-U2 is is used for non-destructive hardness testing of: metals and
...
alloys by scales of hardness: Rockwell (HRC), Brinell (HB), Vickers (HV); non-ferrous metals, alloys of iron etc., and using five additional scales for calibration; with tensile strength (Rm) scale determines the tensile strength of carbon steel pearlitic products by automatic recalculation from Brinell (HB) hardness scale.
>

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.
>

XRHRobotStar

In high volume industries like automotive the requirement for a hundred percent X-ray inspection c
...
reates a bottleneck in the production. The XRHRobotStar is a fully Automated Defect Recognition (ADR) capable robot-system that allows an ultra-fast in-line inspection.
>

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