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LECOEUR ELECTRONIQUE
The Specialist of electronics for ultrasonic testing.
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Technical Discussions
miral
miral
21:33 Nov-21-2013
measuring height of defect in UT

Hi
Is there any method to measure height of a defect in conventional UT without plotting beam profile?

if yes which standard has mentioned it?

    
 
 Reply 
 
Ed Ginzel
R & D, -
Materials Research Institute, Canada, Joined Nov 1998, 1266

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1266
13:25 Nov-22-2013
Re: measuring height of defect in UT
In Reply to miral at 21:33 Nov-21-2013 (Opening).

Miral, there is an ASTM standard (E-2192) called Standard Guide for
Planar Flaw Height Sizing by Ultrasonics. This provides a general description of some options that use tip diffraction techniques. These do NOT use beam pressure boundary methods.

    
 
 Reply 
 
Hamid
Engineering, Researcher
Ecole de technologie superieure, Canada, Joined Sep 2012, 59

Hamid

Engineering, Researcher
Ecole de technologie superieure,
Canada,
Joined Sep 2012
59
17:34 Nov-25-2013
Re: measuring height of defect in UT
In Reply to Ed Ginzel at 13:25 Nov-22-2013 .

Ed, you mean there is no standard to use signal amplitude for measuring the defect height? As I know, in tip diffraction techniques, we use the time difference between the signals diffracted by the two tips not the signal amplitude.

I have the same problem as Miral.

    
 
 Reply 
 
Ed Ginzel
R & D, -
Materials Research Institute, Canada, Joined Nov 1998, 1266

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1266
20:09 Nov-25-2013
Re: measuring height of defect in UT
In Reply to Hamid at 17:34 Nov-25-2013 .

Hamid, using conventional UT there is a popular amplitude method called MaxAmp. Effectively it attempts to identify the last peak of a flaw indication in the vertical plane and then uses a 10% drop. You plot the soundpath along the centre axis of the beam from the exit point where the probe was located for this 10% drop at the last peak.
I think Andrew Cunningham has provided some graphic guidance on this popular old technique.

    
 
 Reply 
 
andrew cunningham
NDT Inspector
Canada, Joined Jun 2008, 238

andrew cunningham

NDT Inspector
Canada,
Joined Jun 2008
238
00:46 Dec-03-2013
Re: measuring height of defect in UT
In Reply to Ed Ginzel at 20:09 Nov-25-2013 .

Download max amp sizing

Hi Miral
Thank you Ed
Cross sectional sizing was once described to me as the black art of ultrasonic’s (by a melodramatic twat) Maximum Amplitude technique (Max Amp) is so easy to demonstrate, but when put into words on paper, it can be open to miss-interoperation.
Theory: To use only the most sensitive part of the transducer, because it is most efficient at turning mechanical energy into electrical. It is assumed to be the center point of the transducer.
Indexing the probe: Place the probe on a IIW V1 A2 facing the 100mm or 4” radius and maximize the signal. Mark with a fine line on the probe side at the 100mm or 4” scribed line on the block. All points from now will be marked from this index point.
Finding the true angle of the probe: Use either an IIW A5 profile block or continue with the V1. Maximize the reflected signal from the smallest hole from as far away as possible. Draw a line through the center of the hole to the index point of the probe. Measure the angle of this line with a good protractor. DO NOT USE an ASME BLOCK unless uniformity of grain size is guaranteed.
Making a plotter: Draw on clear x-ray film, square off the corners by cutting. Draw the probe angle from the corner. Measure and mark every centimeter and millimeter, along the top of the film and down the angle line. Starting at the top corner, the top measurement is for surface distance to a datum (often the weld center line and on the angle is the sound path, from the index to the reflector.
IIW A5: If you have an A5 block, you will note that there is a cluster of about 7 side drilled holes. These holes are good to practice on. Scan the block to locate these holes. You will note that when the probe is static, the holes, although are the same size, are of a different amplitude. However, when you traverse the probe all their amplitudes change. With Max Amp we are only interested in each part of the signal when it is at its Maximum Amplitude. Push the probe forward until all the reflectors have fallen into the time base. Pull the probe backwards, as the cluster of reflectors rise at different rates from the time base, as each and every one reaches its own maximum amplitude, you will record the surface distance from the datum (corner) and its sound path measurement.
These numbers can be transcribed onto paper as physical measurements. When drawn out you will have a 1:1 scale drawing of the reflectors.
Draw 1:1 scale drawings of the cross section of the weld. Use the same principals and you will size and position the reflector found.
I would strongly advise practicing on side drilled holes to perfect your skills.
Note that lack of side wall fusion should be mapped (plotted) through the weld side of the defect, as you get more reflectors from the rough side.
    
 
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