Phased Array Ultrasonic Testing

Phased Array Ultrasonic Testing: Your Complete Guide

phased array ultrasound testing

For volumetric flaw detection in various material and weld inspection applications, many industries have adopted phased array ultrasonic testing (PAUT)—advanced non-destructive testing (NDT) technology. Industries have used this method as an alternative to conventional ultrasonic testing (UT) and radiographic NDT, among other approaches. Its detailed visual analysis and reporting capabilities have ensured the identification of both major and minor cracks, inclusions, and corrosion in greater detail. Industries including aerospace, oil and gas, and power generation are increasingly using PAUT technology to improve the quality of their components. Here we will discuss PAUT technology and its use and applicability for safe and efficient industrial operations.    

The Principle Behind PAUT

Conventional UT utilizes a single transducer that emits an ultrasonic beam, anywhere between the range of 0.1 to 50 MHz onto the equipment or component being tested. Depending upon the material and presence of anomalies within the component, the signal is reflected back in varying manners which can then be analyzed to assess the extent of the flaw.

In comparison, the PAUT method makes use of series of transducers (usually 16 to 256 individual elements) made up of piezoelectric crystals in a single assembly. Each transducer can be pulsed at different times for constructive interference and focused individually without the need to steer the probe across the component. The timed delays help in the optimization of the focal point and beam angle.  Unlike conventional UT, the ability to optimize the focus and angle greatly improves the potential to identify flaws across different types of complex geometries.

PAUT has been effective in inspecting components with varying geometry, thickness, and metallurgical properties to identify flaws such as stress-induced cracking, corrosion, inclusion, and other types of discontinuities. Inspection across such varying components is made possible with different types of scanning abilities, these include: 

  • Sectorial scanning: A sectorial scan is performed by utilizing the phased array to electronically control the ultrasonic beam through a range of angles. A single transducer is used to inspect the component at several angles. This provides a great alternative to the need for utilizing multiple transducers in conventional UT and provides speedy and accurate volumetric inspection.  
  • Electronic scanning: Electronic scanning ensures that manual inspection performed with the UT probe is done by moving the beam across the axis without the need for any mechanical movement of the transducer. As the scan is performed across the length at a constant angle, the result is equivalent to conventional UT corrosion mapping or shear wave inspection.
  • Depth-focus scanning: This method utilizes a single focused pulse to sweep across the axis of the component. This pulse can be optimized and refocused along different focal depths during the scanning process.     

Why Choose PAUT as Your NDT Method?

Across industries and operations, PAUT offers many advantages compared to conventional UT or other NDT methods. Its ease of use, high precision, and speedy inspection has made it a popular choice for flaw detection. Some of these advantages include fast and accurate inspection, simplified testing, and inspection reliability. 

Fast and Accurate Inspection

Multiple transducers within a single assembly allow PAUT to cover a wider area during inspection. This can facilitate a reduction in the time involved in testing. With the software in use for test parameter optimization such as for beam focus and angle, the time required by manual adjustment can also be reduced. The adjustable parameter also means a wider area can be covered in search of flaws like stress corrosion cracking or HTHA (High-Temperature Hydrogen Attack) flaws which could have likely been missed with conventional UT. Thus, PAUT can help in maintaining speed and accuracy. 

Simplified Testing

PAUT can require less time and effort for setup and calibration. Computer control allows for faster and easier optimization. With some manual controls out of the equation, error can be minimized, and the accuracy of inspection is easier to maintain across simple and complex geometries.

Inspection Reliability

With PAUT, beam size and focus can be optimized to allow for image capture and flaw detection in a wide range of angles and depths. With advanced and improved tools and scanning ability, the reliability of inspection can be improved.  

Phased Array Ultrasonic Testing Resources and Applications

The many advantages of PAUT have enabled the method to be used by industries like aerospace or oil and gas in their wide range of NDT applications involving the inspection of dissimilar metal welds and composite materials, to name a few. Here, we have compiled a list of resources that explain PAUT’s applicability as a major inspection solution.

Product Recommendations for Phased Array Ultrasonic Testing 

To help you meet your industrial precision and quality standards, Zetec offers a wide range of NDT solutions. We have compiled a list of our PAUT solutions for advanced flaw detection to assist you in the selection of suitable NDT instruments.


NDT Technology

Product Recommendation(s)

Generic Ultrasonic TOPAZ Family of Instruments

WELD Crawler

NDT Sweeper Scanner
Austenitic Weld Ultrasonic TOPAZ Family of Instruments

WELD Crawler
Composite Structures Ultrasonic TOPAZ Family of Instruments

WELD Crawler

NDT Sweeper Scanner
Carbon Steel Ultrasonic TOPAZ Family of Instruments

NDT Sweeper Scanner

HTHA Ultrasonic TOPAZ64 Instrument
Pipe Elbows Ultrasonic TOPAZ Family of Instruments

ElbowFlex Scanner

Industries have relied upon PAUT as a primary inspection method to identify cracks, corrosion, and other types of flaws in their crucial weld and metallurgical inspection applications. The accuracy, precision, ease-of-use, and efficiency of PAUT allow technicians to easily perform the inspection, visualize flaws, and identify the potential mitigation measures. With early and detailed identification of difficult-to-detect flaws with PAUT, industries can reduce risks and ensure safety and productivity in their operation.

Zetec is a leading name you can trust for your crucial PAUT and other NDT solutions requirements for your industrial inspection needs. For more information, contact us today.