Phased array ultrasonics

<h2 id="principle-of-operation">Principle of operation</h2>
<p>The PA probe consists of many small <a href="/facts/Ultrasonic_transducer/6Ala5r9z">ultrasonic transducers</a>, each of which can be pulsed independently. By varying the timing, for instance by making the pulse from each transducer progressively delayed going up the line, a pattern of constructive interference is set up that results in radiating a quasi-plane ultrasonic beam at a set angle depending on the progressive time delay. In other words, by changing the progressive time delay the beam can be steered electronically. It can be swept like a search-light through the tissue or object being examined, and the data from multiple beams are put together to make a visual image showing a slice through the object.
</p>
<h2 id="use-in-industry">Use in industry</h2>
<p>Phased array is widely used for <a href="/facts/Nondestructive_testing/Czz0Vt0B">nondestructive testing</a> (NDT) in several industrial sectors, such as <a href="/facts/Construction/58eqDhy9">construction</a>, pipelines, and <a href="/facts/Power_generation/Uo6mQQ1T">power generation</a>. This method is an advanced NDT method that is used to detect discontinuities i.e. cracks or flaws and thereby determine component quality. Due to the possibility to control parameters such as beam angle and focal distance, this method is very efficient regarding the defect detection and speed of testing.<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a> Apart from detecting flaws in components, phased array can also be used for wall thickness measurements in conjunction with <a href="/facts/Corrosion/lIC7H4we">corrosion</a> testing.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a><a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a>
Phased array can be used for the following industrial purposes:
</p>
<ul><li>Inspection of welds<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a></li>
<li>Thickness measurements</li>
<li>Corrosion inspection</li>
<li>PAUT Validation/Demonstration Blocks<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a></li>
<li>Rolling stock inspection (wheels and axles)</li>
<li>PAUT & TOFD Standard Calibration Blocks</li></ul>
<h2 id="features">Features</h2>

<ul><li>The method most commonly used for <a href="/facts/Medical_ultrasonography/Ju5BFuuV">medical ultrasonography</a>.</li>
<li>Multiple probe elements produce a steerable and focused beam.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a></li>
<li>Focal spot size depends on probe active aperture (A), wavelength (λ) and focal length (F).<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> Focusing is limited to the near field of the phased array probe.
<ul><li>
  
    
      
        
          Focal spot size
        
        =
        F
        λ
        
          /
        
        A
      
    
    {\displaystyle {\text{Focal spot size}}=F\lambda /A}
  
</li>
<li>
  
    
      
        
          Near Field
        
        =
        
          A
          
            2
          
        
        
          /
        
        4
        λ
      
    
    {\displaystyle {\text{Near Field}}=A^{2}/4\lambda }
  
</li></ul></li>
<li>Produces an image that shows a slice through the object.</li>
<li>Compared to conventional, single-element <a href="/facts/Ultrasonic_testing/MNBrJjuP">ultrasonic testing</a> systems, PA instruments and probes are more complex and expensive.</li>
<li>In industry, PA technicians require more experience and training than conventional UT technicians.</li></ul>
<h2 id="standards">Standards</h2>
<p><a href="/facts/European_Committee_for_Standardization/BwwUrMgy">European Committee for Standardization</a> (CEN)
</p>
<ul><li>prEN 16018, <i>Non destructive testing - Terminology - Terms used in ultrasonic testing with phased arrays</i></li>
<li>ISO/WD 13588, <i> Non-destructive testing of welds – Ultrasonic testing – Use of (semi-) automated phased array technology</i></li></ul>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Phased_array/5wvA9WLV">Phased array</a> (general theory and electromagnetic telecommunications).</li>
<li><a href="/facts/Phased_array_optics/6QV5wMWr">Phased array optics</a></li></ul>

<h2 id="books">Books</h2>
<ul><li><i><a href="http://www.asme.org/Codes/Publications/BPVC/Boiler_Pressure_Vessels_Code.cfm">ASME Boiler and Pressure Vessel Code</a></i>. American Society Of Mechanical Engineers, 2013. Section V — <i>Nondestructive Examination</i>. [See Article 4 — <i>Ultrasonic Examination Methods for Welds</i>. Para E-474 <i>UT-Phased Array Technique</i>]</li></ul>
<h2 id="external-links">External links</h2>
<ul><li><a href="http://www.egr.msu.edu/~fultras-web/"><i>FOCUS - Fast Object-oriented C++ Ultrasound Simulator</i></a> [MATLAB routines for creating and simulating phased arrays]</li>
<li><a href="http://www.explorelearning.com/index.cfm?method=cResource.dspDetail&ResourceID=37">Phased array animated simulator</a> [registration required after 5 minutes' use]</li>
<li><a href="http://www.olympus-ims.com/en/ndt-tutorials/phased-array/">Phased Array Tutorial</a>  Education resource from Olympus</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Corrosion under pipe support inspection. Retrieved on July 13, 2012. <a href="http://www.oilfieldtesting.co.uk/corrosion-under-pipe-support-inspection.php" target="_blank">http://www.oilfieldtesting.co.uk/corrosion-under-pipe-support-inspection.php</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Phased Array (PA). Retrieved on July 13, 2012 <a href="http://www.tuv.com/en/corporate/business_customers/materials_testing_and_inspection/advanced_ndt/phased_array/phased_array.jsp" target="_blank">http://www.tuv.com/en/corporate/business_customers/materials_testing_and_inspection/advanced_ndt/phased_array/phased_array.jsp</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Corrosion Mapping with Phased Array Ultrasonics. 2011 API Inspection Summit and Expo. Retrieved on July 13, 2012. <a href="https://massless.info/images/MCarte_Corrosion_Mapping_2.pdf" target="_blank">https://massless.info/images/MCarte_Corrosion_Mapping_2.pdf</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>ASTM, E2700 (2012). Nondestructive Testing, vol 3.03, Contact Ultrasonic Testing of Welds using Phased Arrays. Conshohocken, PA: American Society for Testing of Materials. pp. 1536–44. ISBN 978-0-8031-8729-0.{{cite book}}:  CS1 maint: numeric names: authors list (link) <a href="978-0-8031-8729-0" target="_blank">978-0-8031-8729-0</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
<li id="fn:5"><p>"Nde Flaw Tech". <a href="http://www.ndeflawtechnologies.com/paut_validation_block.html" target="_blank">http://www.ndeflawtechnologies.com/paut_validation_block.html</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li>
<li id="fn:6"><p>ASTM, E2491 (2012). Nondestructive Testing vol 3.03, Evaluating Phased Array Characteristics of Phased Array Ultrasonic Testing Instruments and Systems. Conshohocken, PA: American Society for Testing of Materials. pp. 1358–75. ISBN 978-0-8031-8729-0.{{cite book}}:  CS1 maint: numeric names: authors list (link) <a href="978-0-8031-8729-0" target="_blank">978-0-8031-8729-0</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li>
<li id="fn:7"><p>Birring, Anmol (September 2008). "Selection of Phased Array Parameters for Weld Testing". Materials Evaluation. <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li>
</ol>

Phased array ultrasonics open-in-new

Phased array ultrasonics