Ultrasonic Sound Testing (USD)
Ultrasonic Testing
(UT) uses high frequency sound energy to conduct examinations and make
measurements. Ultrasonic inspection can be used for flaw detection/evaluation,
dimensional measurements, material characterization, and more. To illustrate
the general inspection principle, a typical pulse/echo inspection configuration
as illustrated below will be used.
A typical UT inspection system consists of several functional units, such as the pulser/receiver, transducer, and display devices. A pulser/receiver is an electronic device that can produce high voltage electrical pulses. Driven by the pulser, the transducer generates high frequency ultrasonic energy. The sound energy is introduced and propagates through the materials in the form of waves. When there is a discontinuity (such as a crack) in the wave path, part of the energy will be reflected back from the flaw surface.
The reflected wave signal is transformed into an electrical signal by the transducer and is displayed on a screen. In the applet below, the reflected signal strength is displayed versus the time from signal generation to when a echo was received. Signal travel time can be directly related to the distance that the signal traveled. From the signal, information about the reflector location, size, orientation and other features can sometimes be gained.
Ultrasonic Inspection is a very useful and versatile NDT method. Some of the advantages of ultrasonic inspection that are often cited include
- It is sensitive to both surface and subsurface discontinuities.
- The depth of penetration for flaw detection or measurement is superior to other NDT methods.
- Only single-sided access is needed when the pulse-echo technique is used.
- It is highly accurate in determining reflector position and estimating size and shape.
- Minimal part preparation is required.
- Electronic equipment provides instantaneous results.
- Detailed images can be produced with automated systems.
- It has other uses, such as thickness measurement, in addition to flaw detection.
As with all NDT methods, ultrasonic inspection also has its limitations, which include.
- Surface must be accessible to transmit ultrasound.
- Skill and training is more extensive than with some other methods.
- It normally requires a coupling medium to promote the transfer of sound energy into the test specimen.
- Materials that are rough, irregular in shape, very small, exceptionally thin or not homogeneous are difficult to inspect.
- Cast iron and other coarse grained materials are difficult to inspect due to low sound transmission and high signal noise.
- Linear defects oriented parallel to the sound beam may go undetected.
- Reference standards are required for both equipment calibration and the characterization of flaws.
The above introduction provides a simplified introduction to the NDT method of ultrasonic testing. However, to effectively perform an inspection using ultrasonics, much more about the method needs to be known.
Related blogs :
http://techshoreinspections.blogspot.com/2017/01/Techshore-Inspection-Services-ndt-ultrasonic-testing.html
http://techshoreinspections.blogspot.com/2016/12/Techshore-Inspection-Services-liquid-penetrant-test.html
http://techshoreinspections.blogspot.com/2016/10/ultrasound-testing-techniques-contact.html
http://techshoreinspections.blogspot.com/2016/10/ultrasound-testing-technique-through.html
http://techshoreinspections.blogspot.com/2016/10/ultrasound-testing-techniques-pulse.html
http://techshoreinspections.blogspot.com/2016/10/ultrasonic-testing-techniques.html
http://techshoreinspections.blogspot.com/2016/10/ultrasound-generation-principles-of.html
http://techshoreinspections.blogspot.com/2016/10/ndt-ultrasonic-testing-beam-explained.html
http://techshoreinspections.blogspot.com/2016/10/introduction-to-ndt-non-destructive.html
http://techshoreinspections.blogspot.com/2016/09/techshore-non-destructive-testing-ndt.html
http://techshoreinspections.blogspot.com/2016/09/techshore-inspection-services-explains_6.html
Documents :
https://www.slideshare.net/techshoreinspectionservices/civil-engineering-process-of-well-treatment-techshore
https://www.slideshare.net/techshoreinspectionservices/ndt-ultrasonic-testing-techshore
https://www.slideshare.net/techshoreinspectionservices/ndt-liquid-penetration-test-techshore
Additional references:
https://www.youtube.com/channel/UCfufdF0-Hs3sLu1IX52ZJYA/videos
http://techshore.in/blog
http://techshore-updates.blogspot.in/
https://techshore-inspection-services.blogspot.in/
https://techshoreinspectionservices.blogspot.in/
https://techshoreinspections.blogspot.in/
You Tube Tutorials :
https://www.youtube.com/watch?v=bfW1eL0aTlU
https://www.youtube.com/watch?v=URlwZ3R94u8
https://www.youtube.com/watch?v=6w9Cl58-p34
https://www.youtube.com/watch?v=ZVnsx5VC77g
https://www.youtube.com/watch?v=3ZD4je9Fbn8
Good article
ReplyDeleteIt would be wonderful if more data on NDT is published . Various types of NDT its advantages and disadvantages etc ......
ReplyDeleteVery informative..
ReplyDeleteIs this method is applicable for detecting cracks in live pipes, for example water is flowing through the pipe due to this flow pipe is vibrating in this condition can we use this method.
ReplyDeleteIts better to inspect such pipes befor the water is being supplied through the pipe,as this procedure requires careful and keen handling of probes on metal surface,wich means your test surface should be absaloutely fixed at a place.
DeleteWhat are pulser/receiver, transducer, and display devices ?
ReplyDeleteHow is the mechanism or process that happens inside these devices?
How are these devices helping the USD process ?
Could u please provide the detailed explanation on these aspects ?
Instead of diagrams why do not you include real life pictures , videos etc . Its makes the audience better assimilate the concepts
ReplyDeleteThis comment has been removed by the author.
DeleteDear SaNju
DeletePlease find the youtube video that will answer your query .
URL : https://www.youtube.com/edit?video_id=URlwZ3R94u8&video_referrer=watch
Please feel free to comment or post your queries .
Could u please explain more on how the defect is detected using this process . How is the sound waves reflected back and how is it measured . Why do we have to use crystals ?
ReplyDeleteTechshore should include real life examples or videos or actual testing procedure for better understanding .
What is the operating frequency of the transducer ? Is the transducer single element or multi element ? What type of material is used for making the transducer ?
ReplyDeleteFrequencies in between 2 to 4 mega hertz is quite used in ultrasonic testing.transducer is an equipment used to transmit sound energy into test material and its a single unit.
DeleteMain component in a transducer is a piezo electric crystal wich produces sound energy.
Hi! Got a chance to go through this article and its really a pleasing one! simple and well contented! On my personal level, i highly suggest the author to add more data about NDT method and industrial and medical applications of ultrasonic testing. As I heard, Ultrasonic plays a vital role in the so mentioned sectors. ( I would also like to suggest adding more application oriented diagrams for easy conveyance of the concept.)
ReplyDeleteHighly appreciable work!Expecting more articles like this in future!
Dear Appu ,
DeleteThank You for your valuable feedback .
Please visit the below mentioned URL which will answer all your queries
1. https://en.wikipedia.org/wiki/Ultrasonic_transducer
2. https://books.google.co.in/books?id=KUd6bLOtrxoC&pg=PA6&lpg=PA6&dq=crystal+ringing+time+of+a+probe&source=bl&ots=7uE2o4icY7&sig=deGFnPsjM5zvPE_GrhpraDHmu5Q&hl=en&sa=X&ved=0ahUKEwi2kO-t48zPAhWIQo8KHe5BCtIQ6AEIIDAB#v=onepage&q=crystal%20ringing%20time%20of%20a%20probe&f=false
3. http://traktoria.org/files/sonar/transducer/simple_transducer_intro.pdf
This is an informative article ad it explains a lot about the ndt and especially the testing and application of NDT at various engineering field.expecting more article from the author in the nearby future
ReplyDeleteExplained everything in simple language. Good article.
ReplyDeleteexcellent article ..
ReplyDeletevery informative .
Well Written..Really it's an informative article..
ReplyDeleteThis article is really imformative to me , because this information is help me do a wonderful project.... And the techshore was using very simple language to explain this.And i have one more request to you, that is please include the advantages and dis advantages to this article, that will more helpfull to me and other people to do like projects and seminar about this topic.....
ReplyDeleteArticle is good. Got a basic idea about the ultrasonic test. The basic principle is defined well. Also came to know about the advantages and limitations of this method very well.
ReplyDeleteThis article is useful to know about thé basics Of UT method using in NDT
ReplyDeleteThis article clearly explain about UT method in NDT
ReplyDelete