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 -
7508 views
Technical Discussions
KUDRET AKIN
Engineering,
CALIBRATION LAB, Turkey, Joined Dec 2012, 8

KUDRET AKIN

Engineering,
CALIBRATION LAB,
Turkey,
Joined Dec 2012
8
11:03 Jan-27-2013
calibration of UT transducers

Hello, we have been using immersion and contact type transducers.
Some of thems have been used with small flaw detectors and others have been used in TT bridge systems. I am seaching new companies which can calibrate them according with the international std. documents.
Could you please send any inf. about these companies?

Thanks.

 
 Reply 
 
Michel Couture
NDT Inspector,
consultant, Canada, Joined Sep 2006, 889

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
889
18:47 Jan-27-2013
Re: calibration of UT transducers
In Reply to KUDRET AKIN at 11:03 Jan-27-2013 (Opening).

If I get your question right, you are wasting your time. Transducers are fabricated and come the way they are. There is no calibration of the transducers per say. If you want to calibrate your system, that is another story and yet a simple one. Your level 2 technicians should be able to figure this one out. All they need is the proper calibration blcok according to the standard you are working to.

As for the transducers themselves, all I can say is to purchase them from a reputable manufacturer. They are many out there and one of them will meet your requirements.

 
 Reply 
 
Sudheer Jai Krishnan
Sudheer Jai Krishnan
22:56 Jan-27-2013
Re: calibration of UT transducers
In Reply to Michel Couture at 18:47 Jan-27-2013 .

Hi Michel,

Greetings. If i am right, Kudret is asking for an yearly calibration of transducers , may be as per ASTM-E-1065

This is a requirement for aviation companies where they do request an yearly calibration of transducers which their suppliers use for NDT examinations of Composites. I dont know exactly about the agencies that calibrate the Ultrasonic Transducers, but there are some who perform these calibrations.

 
 Reply 
 
Ed Ginzel
R & D, -
Materials Research Institute, Canada, Joined Nov 1998, 1300

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1300
00:39 Jan-28-2013
Re: calibration of UT transducers
In Reply to Sudheer Jai Krishnan at 22:56 Jan-27-2013 .

Sudheer, indeed, some industries require periodic checks of the probes. This will require a baseline assessment so subsequent tests are compared to the baseline. E-1065 is a nice option because it allows the contracting parties to agree on the parameters to monitor and the methods to use. Once agreed, the process can then be described in a procedure and the records of the tests maintained for review for any deterioration/change.
There are Euro norms that describe the requirements of a probe being made by the manufacturer. After it leaves the manufacturer the user could have an incoming inspection procedure (that could be the baseline) to compare the performance of the probe to the minimum requirements specified by the user.
These steps require a programme to be in place so it may be difficult to impose on old probes, but as new ones are entered into the system the process could be used to monitor performance.

 
 Reply 
 
S V Swamy
Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex , India, Joined Feb 2001, 787

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
787
02:13 Jan-28-2013
Re: calibration of UT transducers
In Reply to Ed Ginzel at 00:39 Jan-28-2013 .

We did look at immersion systems with necessary instrumentation to check the frequency, the focal spot size (for focused probes) etc. and were in fact toying with the idea of building a system ourselves (because of our special circumstances).

We discussed with our end users (NPCIL) and regulators and agreed that the best way of handling this situation is 'fitness for use' - use the transducer for the specific test application and see whether the required sensitivity is being obtained. We were also looking at the changes if any in the echo patterns and changes in the gain needed to obtain the needed detection sensitivities.

Many times, the connecting cables were giving more problems than the transducers themselves.

If the specification from the customer demands such a calibration, it may be necessary to invest in such a system or look for qualified agencies. Otherwise, the regular calibration of the system (transducer, cable, electronics taken as a whole) with the specific calibration standards should be sufficient.

A written procedure should address these aspects and should be approved by all the stakeholders.

Best regards

Swamy

 
 Reply 
 
John Brunk
Engineering, NDT Level III
Self employed, part-time, USA, Joined Oct 1999, 162

John Brunk

Engineering, NDT Level III
Self employed, part-time,
USA,
Joined Oct 1999
162
05:50 Jan-28-2013
Re: calibration of UT transducers
In Reply to Sudheer Jai Krishnan at 22:56 Jan-27-2013 .

What is sometimes required for transducers is usually called "characterization". Calibration implies that if the device in question has gone out of calibration while in service it can possibly be fixed to operate properly again. Transducers whose operating characteristics change excessively over time can rarely be fixed. Characterization of an immersion transducer may include a variety of parameters specified by the user. It is necessary to fully specify the ultrasonic system used for characterization: whether the target is a flat plate, or a rod or sphere of a particular diameter; pulser type and pulse rise time, width, etc.; receiver passband and so on. All these things must be the same to properly compare the performance of a transducer over time, or two compare a group of transducers with each other. In a very few instances for very difficult testing requirements I had to pick the "best" transducers from a group and order more with just the same bandwidth, focal spot size, etc. all measured with the same equipment and settings. This is expensive unless the manufacturer has other customers for those that are not the most perfectly matched. Periodic retesting of a transducer is useless unless it is always done with the same equipment and setup each time.

Most if not all contact transducers are also characterized to some extent by the manufacturers. Sometimes the test data is available for a small extra cost at the time of purchase. It is much easier to make large numbers of 2 MHz contact transducers for weld testing that are close enough to "identical" for practical purposes, much harder to do the same with a number of of 25 MHz immersion transducers with a spherical focus in water of 1.00" to 1.04".

 
 Reply 
 
KUDRET AKIN
Engineering,
CALIBRATION LAB, Turkey, Joined Dec 2012, 8

KUDRET AKIN

Engineering,
CALIBRATION LAB,
Turkey,
Joined Dec 2012
8
10:40 Jan-28-2013
Re: calibration of UT transducers
In Reply to KUDRET AKIN at 11:03 Jan-27-2013 (Opening).

Hello, thanks for your replies.
I want to explain my request in more detail. We have been using 3 big Ultrasonic test systems with water sprinkler and dual TT immersion transducers. We are also using the small ultrasonic test devices with PE contact transducers. And for many years we have sent our TT & PE transducers to the manufacturers for calibration (characterization) annualy. Some std documents available for the transducer calibration and evaluation of calibration tests. These are ASTM 1065 and I+D-E 296B etc.
Recently some companies didn't want to make calibration of transducers. Therefore we are looking for companies who make transducer calibration according to std. docs.Some calibration paramaters are; Bandwith, Peak Frequency, Damping factors, Beam Symmetry values X, Y etc.
Regards.

 
 Reply 
 
Andrew Hurrell
Consultant, Ultrasonic Transducer Production
Precision Acoustics Ltd, United Kingdom, Joined Apr 2000, 25

Andrew Hurrell

Consultant, Ultrasonic Transducer Production
Precision Acoustics Ltd,
United Kingdom,
Joined Apr 2000
25
11:39 Jan-28-2013
Re: calibration of UT transducers
In Reply to KUDRET AKIN at 10:40 Jan-28-2013 .

Hi Kudret

As you'll have seen from the previous comments there are various ways of characterising transducer with test blocks etc. However if you are keen to have a full beam characterisation with both spectral and beamwidth measurements then we can assist. If it is your preference to have us do the characterisation for you we can. Slternatively if you wanted the capability in-house then we could also supply you with the equipment to enable you to do so. Several of the exhibitors on this this forum already Precision Acoustics UMS systems (or components thereof) for transducer characterisation

Feel free to send me an email if you need additional information

Best wishes

Andrew

 
 Reply 
 
Sudheer Jai Krishnan
Sudheer Jai Krishnan
11:56 Jan-28-2013
Re: calibration of UT transducers
In Reply to Ed Ginzel at 00:39 Jan-28-2013 .

Hello Ed

Greetings of the day and thanks for the reply. As i have mentioned earlier and as you have told, it is one the requirement for some of the aerospace companies that do UT. In fact, if an Aerospace company gets a NADCAP accreditation for their NDT facility, then it is a must that we should perform the calibration of transducers every year.

 
 Reply 
 
Gerhard Splitt
R & D,
Private, Germany, Joined Nov 1998, 38

Gerhard Splitt

R & D,
Private,
Germany,
Joined Nov 1998
38
15:47 Jan-28-2013
Re: calibration of UT transducers
In Reply to Sudheer Jai Krishnan at 11:56 Jan-28-2013 .

The European standard EN 12668-2 is valid for the calibration of UT transducers. Methods are described to measure the probe parameters as mentioned by Kudret: like Bandwith, Peak Frequency, Damping factors, Beam Symmetry values X, Y and some other more. Normally probe manufacturers will do the calibration. There are some other "independent" institutions like BAM in Berlin, Germany, who can also do the job.
EN12668-3 gives calibration procedures for the system = probe + Instrument. This has do be performed by the operator / test engineer of the test company.

Regards,
Gerhard

 
 Reply 
 
Michel Couture
NDT Inspector,
consultant, Canada, Joined Sep 2006, 889

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
889
23:13 Jan-28-2013
Re: calibration of UT transducers
In Reply to Gerhard Splitt at 15:47 Jan-28-2013 .

I understand the characterisation of transducers. When working at a nuclear plant, we did verify our probes and shoes every 40 hours of use. But can we call this calibration? Except for changing the angle of the shoes by light sanding, the crystal's characteristics remain the way they were made, except of course for aging. So is it calibration?

 
 Reply 
 
Ed Ginzel
R & D, -
Materials Research Institute, Canada, Joined Nov 1998, 1300

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1300
13:30 Jan-29-2013
Re: calibration of UT transducers
In Reply to Michel Couture at 23:13 Jan-28-2013 .

Perhaps some of this divergence is just semantics. In ASTM we are required to use the term standardization when setting the response of an NDT instrument to a reference standard so as to establish a reproducible response. Any place I have worked in in industry refers to that process as calibration. ASTM reserves calibration to the process of comparing the response of an NDT instrument to a nationally traceable standard. If an immersion probe was sent to a national lab where the beam profile was made using a 3mm diameter stainless steel ball, the ball diameter and acoustic impedance "could" be assessed against a national standard so the characterisation of the beam MIGHT be considered a calibration. Kudret's requirement for assessment of bandwidth and peak frequency will require controlled pulser parameters, an agreed target and even an agreed couplant and couplant path length.
As Gerhard pointed out, many manufacturers have a standard they work to so this could be a starting point to assess if the old probes still fall within tolerance.

 
 Reply 
 
Gerhard Splitt
R & D,
Private, Germany, Joined Nov 1998, 38

Gerhard Splitt

R & D,
Private,
Germany,
Joined Nov 1998
38
17:06 Jan-29-2013
Re: calibration of UT transducers
In Reply to Ed Ginzel at 13:30 Jan-29-2013 .

To make the wording just a little bit clearer: Many probe suppliers deliver the probes with a data sheet, giving typical data of the probe type with tolerances, or the probe is delivered with an individual certificate of performance, stating the individual (measured) data of the specific probe, like frequency, band width, angle, beam profile etc.. The European standard EN 12668-2 provides rules, which probe data have to be measured, describes the procedures, how to do this, and gives tolerances for each parameter. As Ed mentioned, special equipment is needed to do this certification.
There are other standards, which ask for a recertification of the probe after a certain period of time. I guess this "recertification" is what Kudret is looking for. The recertification should prove that the probe is still in good conditions, meaning that the probe is fulfilling the tolerances of the EN 12668-2 or of the probe manufacturer, whichever is narrower. Again special equipment is needed for recertification.

 
 Reply 
 
Michel Couture
NDT Inspector,
consultant, Canada, Joined Sep 2006, 889

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
889
01:18 Jan-30-2013
Re: calibration of UT transducers
In Reply to Gerhard Splitt at 17:06 Jan-29-2013 .

Gerhard,
Your read my mind.

 
 Reply 
 
Mike
Director,
Guangzhou Doppler Electronic Technologies Co.,Ltd, China, Joined Dec 2012, 14

Mike

Director,
Guangzhou Doppler Electronic Technologies Co.,Ltd,
China,
Joined Dec 2012
14
09:00 Jan-30-2013
Re: calibration of UT transducers
In Reply to Michel Couture at 01:18 Jan-30-2013 .

Totally agree with all message mentioned above,all transducers need calibration step while for high resolution required inspection, esperically for aiation industry, there is no manufacturer can gurantee the warranty period of probes within one years or even long, because the abrasion for each probes is different by different workpiece,the little abrasion cant be check out, that's why we need calibration in those probes regular. According to EN12668-2,there is calibration illustration for all probes, all mentioned topic, such as bandwidth,dampling, peak frequency and others all list right there. This kinds of problem should be solved by cooperate supplier.

 
 Reply 
 
KUDRET AKIN
Engineering,
CALIBRATION LAB, Turkey, Joined Dec 2012, 8

KUDRET AKIN

Engineering,
CALIBRATION LAB,
Turkey,
Joined Dec 2012
8
13:01 Jan-30-2013
Re: calibration of UT transducers
In Reply to KUDRET AKIN at 11:03 Jan-27-2013 (Opening).

Hello everbody again,
Many thanks for your opinions, I've started to get new quatations from some companies for our transducers get calibrated in accordance with std. docs.
Regards.

 
 Reply 
 
Drew Courtright
Drew Courtright
20:02 Mar-10-2020
Re: calibration of UT transducers
In Reply to KUDRET AKIN at 13:01 Jan-30-2013 .

Sorry I am late to the party, but my company re-certifies transducer performance to ASTM-E-1065. There is no such thing a calibration, per se, but we do give you a test report which can be compared from the original.

 
 Reply 
 
Henry Herrera
R & D,
UT Quality, Canada, Joined Jun 2000, 19

Henry Herrera

R & D,
UT Quality,
Canada,
Joined Jun 2000
19
21:06 Mar-10-2020
Re: calibration of UT transducers
In Reply to Drew Courtright at 20:02 Mar-10-2020 .

In addition to all the previous comments. Note that ASTM E1065E it is useful to follow for the re-certifications steps but doesn't provide acceptance criteria. EN EN12668-2 is more specific in that sense, defining the acceptance criteria for
-The centre frequency has to be within ± 10% of the frequency quoted in the datasheet.
-The -6 dB bandwidth has to be within ± 15% of the relative bandwidth stated in the datasheet.
-The pulse duration shall not deviate by more than ± 10% from the manufacturer's specification.

Note that the acceptance criteria are against the manufacturer's specification, not the nominal values.

 
 Reply 
 

Product Spotlight

Compact NDT inspection-heads for measurements with active thermography

The compact inspection head is suitable for thermographic ndt tasks. The uncooled infrared camera
...
is specially developed for NDI-tasks and offers a thermal sensitivity until now known only from thermal imagers with cooled detector. All required components and functions are integrated into the inspection-head. You will only need an ethernet cable to connect the sensor with the evaluation system.
>

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.
>

HD-CR 35 NDT Computed Radiography System

Portable high-resolution CR scanner for all radiography applications - weld testing, profile images
...
and aerospace. No matter what type of radiographic testing you are performing, the unique TreFoc Technology of the HD-CR 35 NDT imaging plate scanner always guarantees the highest image quality.
>

Ultrasonic Squirter/Gantry System

TecScan’s NDT Ultrasonic Gantry Systems are industrial Squirter scanners designed for non-destru
...
ctive quality testing and raster scanning of large structures and parts. The Gantry Systems are usually composed of an Industrial Mechanical Scanner and a Control Room with System Workstation.
>

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