Recent Posts

Topic: General Discussion / Powering an Ultrasonic Transducer

has a wonderful writeup about a new toy in the shop, an [url=http://www.osenon.com]Ultrasonic transducer Manufactory[/url]. The 28kHz, 70W bolt-clamped Langevin transducer by itself is not much use, you need a power supply, a horn to focus the energy, and a way to tune it. starts off by showing how to find out the resonant frequency of the transducer, designing and building a high voltage high frequency AC power supply, and how to design a horn.

Not missing the meaning of DIY casts and machines a horn for the transducer with a high level of precision as this will also tune the horn to the correct frequency. Once some brackets are machined the whole setup is put through some fun experiments in water and lemonaide, but the real purpose is to drill fine holes in glass for his home made Panaplex displays.

Topic: General Discussion / Non destructive testing in chennai | Ndt in chennai | Ndt jobs in chennai

INDO TECH INSPECTION SERVICE in chennai are the pioneers in NDT training ASNT Level I and Level II. http://www.indotechnde.com

Topic: General Discussion / Pre-amp for ToFD with Omniscan MX2?

I’ll answer my own question here, yes you do need a pre-amp if you want to get decent ToFD signals with an Omniscan. Olmpus make one http://www.olympus-ims.com/en/scanners/accessor… for about $3000.

Topic: General Discussion / PA/TOFD Inconel Coating

yeah i think it should be the alloy. I’ve had a look at the article, the response from the PA seems ok, i guess we will just have to make a reference block with known flaws and see what kind of detection we get.

Topic: General Discussion / PA/TOFD Inconel Coating

Kevin, is the so-called buttering actually carbon-manganese steel? Isn’t it more common to butter the carbon steel component with the corrosion resistant alloy? An associate of ours has reported on this process with some nice images and overlays! http://www.aitechnologies.biz/inspection_of_wel…

Topic: General Discussion / PA/TOFD Inconel Coating

So i have this Inconel weld with buttering and a coating. Any suggestions or special considerations to tackle this with Phased Array/ToFD for 100% coverage?

Topic: General Discussion / Offshore work

Thanks for the answer Kev. Maybe offshore work is out of reach for this lot over here then, because none of the guys have eddy current certificates, nor any money, to pay the for the survival ticket. And they can hardly survive here, let alone over there :)

I´m working as a sub-contractor for an inspection company called Dekra now. There are about 12 guys here (no Harri though), doing ndt for offshore windmill “bases”, which are going to be shipped somewhere over to norwegian coast (close to Bergen I think it was). Ruukki is the company who´s doing the job here ( www.ruukki.com ). It´s nothing rosy, but I get home for every weekend and also earn lots of money (hehe), so can´t complain.

SAS will now open a direct flight from my hometown to Copenhagen, just when I got off from there. My travelling time would be cut to half with that new flight, so it would make it easier to work somewhere abroad again. But need to see if anything interesting comes up…

Ok, take care. Tomi

Topic: General Discussion / Offshore work

Alright Tomi, how is it going there in Finland? You working with Harri? I’m not really sure about the offshore work availability but i can ask around. You would become instantly more employable if you pay for your survival ticket yourself. To get a regular slot offshore you need to find an NDT company that has a inspection contract with a maintenance company for the routine inspection offshore.

To work in the British sector you’ll need PCN 2 quals. Having an rope access ticket and a desirable inspection qual like eddy current would be a good way to get offshore i would say.

Topic: General Discussion / Offshore work

Hello Kevin,

Just to get some discussion going here on your site, I thought to ask, what are the changes of getting work from offshore, for a person who has never worked there before ? I´m talking about ndt work here of course.

Some guys here in Finland seemed pretty interested, when I got back home from Stavanger and mentioned that the work rythm in offshore could be two weeks work and four weeks off. But you need to have some offshore safety certificates to get there and they cost money, I´m sure, so you need to get on some company payroll first… but which company ? Westcon, Aker…what else was there ?

Is there any realistic changes of getting there ?

Anyway, take it easy there Kevin and keep the probes moving :)

Regards, Tomi Finland

Topic: General Discussion / Pre-amp for ToFD with Omniscan MX2?

Is the general practice still to use a pre-amp when deploying the ToFD technique with an Omniscan?

Topic: General Discussion / Ultrasonic test through paint

Gary,

You have not mentioned the type of ultrasonic test that is to be performed. If it is for discontinuities, what Ed Ginzel mentioned is correct. If it is thickness test, you may need to apply some corrections for the time delay if any through the paint thickness. You would need to prepare some good calibration blocks that represent the job to be tested.

Regards

Swamy Quality Consultant

Topic: General Discussion / Ultrasonic test through paint

Gary, If the paint is well bonded to the metal it may not be an issue. The easiest way yo determine this is to do a transfer value on the plate at several places along the weld. 3-4dB transfer value added to the scanning sensitivity would not be an onerous increase in sensitivity. You may even find that the TV is a negative value. Sometimes the paint thickness impedance matching actually provides a quarter-wave plate effect and you get a constructive interference as the pulse does a small half-cycle ring in the paint layer. Not sure how you deal with a negative TV, but we usually just ignored it (i.e. we did not remove any gain for the scanning).

Topic: General Discussion / Ultrasonic test through paint

Hello all, Just been asked to do a job that has a painted surface. Procedure states that all surfaces are to be free from paint debris grease and other artefacts that may interfere with the examination. Client is reluctant to remove paint as there are a lot of items to inspect and the cost will be extremely high to repaint. Feedback would be greatly appreciated.

Topic: General Discussion / Phased Array Repeat Echoes

Nice one Ed. That icon appears to be missing on v2.9 but you can just go FILE>DATA FILE MERGE. Now i have combined both root scans and the cursors are automatically linked.

Topic: General Discussion / Phased Array Repeat Echoes

Kevin, if using Tomoview you should be able to use the feature they call “Data File Merger”. It is oddly not a feature found in one of the tabs at the top of the screen! Instead, the only place I can see it is as an icon (I am using version 2.8). The icon shows 2 2 small windows with lines going to the right connecting to a larger window. You then give a name to the file that will result upon merging and then add the files to merge. Simply pressing the Add button brings up a browser and you can then select the files to merge.

Topic: General Discussion / Phased Array Repeat Echoes

Thanks Ed. Yeah that does make a lot of sense.

I manually edited the position of the overlay by 6mm, that’s why it’s off center.

We are scanning from both sides but we only have 1 5L16 probe so we have 2 different files. Do you know of a way to combine the files in Tomoview so that the cursors can be linked and therefore analysis from both sides of the weld can be done at the same time?

That’s a simple neat trick to finger damp the area in front of the wedge, i’ll try that.

Topic: General Discussion / Phased Array Repeat Echoes

Kevin, these images (B-scan and S-scan) are from one side only. To first eliminate the signal arriving from the putative far-side of the bevel as a flaw we should look at the S-scan from the other side. As well, the 0mm offset (green scale at bottom of the S-scan) is not centred in the weld. If the offset was not correctly set and the 0mm position is actually at the weld centreline we would also need to consider that this is not actually in the weld proper but is instead slightly off to the right by about 5mm. But the multiples that you asked about should be a clue to the elimination of the first arrival as a flaw!.

There are 2 strong signals after the first arrival. The B-scan shows this condition to run full length and it is almost, but not quite, a constant arrival for the “root” (first arrival). but both the arrival time and the amplitude of the multiples vary. In fact, between about 300-350mm along the scan the root signal is still there and well defined but the multiples have nearly disappeared. The multiples are aptly identified as “multiples” because they are evenly spaced along the timebase.

All this points to a probable mode conversion from the transverse mode striking the root (perhaps excess root reinforcement in a nice rounded shape) and then redirecting up to the cap in compression mode. There is adequate gain that we see the signal bounce off the cap and move straight down to the root where it again reflects to the top (etc.) But we cannot use the image to completely explain the process. The image has us thinking that the beam has moved along a path that is indicated by the black cursor indicating the focal law. Instead, the beam path changed after the interaction with the root. Therefore, instead of travelling another 6mm of depth (as indicated on the A-scan…equivalent to about 12mm of soundpath in transverse mode), the soundpath in compression mode is 1.84 times greater (about 23mm) and directed along a new angle straight up to the cap.

Sorry for the long explanation. I have often seen this effect and it is easily confirmed by touching the cap with a wet finger in front of the probe. The multiples (but not the first arrival) are seen to be dampened. What is perhaps a bit surprising in this case is that you have evidence of the condition for for over 600mm.

Topic: General Discussion / Phased Array Repeat Echoes

ok, so this is a more detailed view with A-Scan and S-Scan:

and here is the scan plan:

Topic: General Discussion / Looking for work?

Does anyone know a Sales Rep with aerospace NDT experience looking for a position in Dallas, TX?

Topic: General Discussion / Current Phased Array Codes & Standards

I’m trying to get a comprehensive list of all current and draft standards that relate to PA. This still seems to be a grey area. Anyone have any comments, or know any of the personalities involved in development of these documents?

• Draft BS EN 16018 Non destructive testing - Terminology - Terms used in ultrasonic testing with phased arrays
• BS EN ISO 13588 Non-destructive testing of welds - Ultrasonic testing - Use of (semi) automated phased array technology
• E 2700 – 09 Standard Practice for Contact Ultrasonic Testing of Welds Using Phased Arrays
• ASME CC 2235-8 Use of Ultrasonic Examination in Lieu of Radiography
• ASTM E2491 - 08 Standard Guide for Evaluating Performance Characteristics of Phased-Array Ultrasonic Testing Instruments and Systems
• ASME CC 2541
• ASME CC 2557
• ASME CC 2558
• EN-2599 Use of Linear Phased Array E-Scan Ultrasonic Examination Per Article 4 Section V Supp 5
• EN-2600 Use of Linear Phased Array S-Scan Ultrasonic Examination Per Article 4 Section V

Topic: General Discussion / Phased Array Repeat Echoes

So i have this PA B-Scan with repeat echoes from the root but I’m not sure exactly what the sound is doing, anyone have an idea? I have an S-Scan from 45 - 70 degrees.

Topic: General Discussion / Experience of NDT training schools

Yeah, i have heard that a lot actually about Talon. That seems to be the general view, i know that they used to get a lot of x-forces guys through there.

Topic: General Discussion / Experience of NDT training schools

ok, lets get this moving, the worst, talon in aberdeen, shut them down!!!, those sheep shaggers got not idea!!! complete cowboys!!!…… and the good , argyll ruane in rotherham, lavender is ok but not as good……

Topic: General Discussion / Upcoming Projects

test

Topic: General Discussion / Looking for work?

Worked at forgemasters 6 years, steel castings forgings yoke prods dye pen