White Papers
Phased Array Performance Evaluation with PhotoElastic Visualization

New instrumentation and a widening range of phased array transducer options are affording the industry a greater potential.  Visualization of the complex wave components using the photoelastic system can greatly enhance understanding of the generated signals.  Diffraction, mode conversion and wave front interaction,together withbeam forming for linear, sectorial and matrix arrays, will be viewed using the photoelastic system.  Beam focus and steering performance will be shown with a range of embedded and surface targets within glass samples.This paper will present principles and sound field images using this visualization system.

Fast total focusing method by a migration approach

The Total Focusing method is an efficient approach to perform ultrasonic imaging of industrial components. It consists in focusing at each point of a reconstruction area by applying coherent summations. The main issue of this method is the computation time which makes real-time imaging difficult for large images. In this paper, we propose to use a migration technique that accelerates the processing. With real data, we show that this method is much faster than the conventional technique and that the signal to noise ratio is significantly increased. Those results demonstrates the great potential of this method for real-time imaging applications.

Small, Flexible and Advanced Phased Array Module for Customizing NDT Applications

Having a small, advanced and open platform phased array (PA) ultrasonic module provides new technological opportunities for both industrial and research applications. Industrial applications can benefit by creating seamless solutions that fit their particular need or niche. A smaller form factor advanced PA mod-ule allows mounting the instrument on a scanner or robotic arm, thus shortening the transducer cable, which provides better signal quality, better integration, avoids cable failures and reduces cost. Researchers require instrumentation that allows access to low-level parameters and raw data from the acquisition unit and the freedom to control and interface to instrumentation with their choice software language. However, key char-acteristics are essential such as a complete phased array feature set, excellent signal-to-noise ratio, fast data throughput, ruggedness, compact form factor and cost effectiveness.

Comparison of conventional technique and migration approach for total focusing

Synthetic aperture focusing technique (SAFT) and total focusing method (TFM) have become popular tools in the field of ultrasonic non destructive testing. In particular, they are employed for detection and characterization of flaws. From data acquired with a transducer array, those techniques aim at reconstructing an image of the inspected object from coherent summations. In this paper, we make a comparison between the conventional technique and a migration approach. Using synthetic and experimental data, we show that the developed approach is faster than the conventional total focusing method but is less flexible. Indeed, the migration approach is adapted to layered objects whereas the standard technique can fit complex geometries. The methods are tested on homogeneous pieces containing artificial flaws such as side drilled holes.

Fast total focusing method for ultrasonic imaging

This work deals with advanced and fast imaging techniques using phased array probes for non destructive evaluation or medical imaging. These methods employ a large amount of summations in order to focus at each pixel of the reconstruction image, which often represent a prohibitive computational cost. We present two acceleration methods, i.e. GPU computation and a migration approach. The GPU computing uses massively parallel computations. The migration approach works in the wavenumber domain and permits a significant improvement in terms of image quality. In this paper, we demonstrate the benefits of these techniques with experimental data captured from an aluminum block containing artificial flaws.

Phased Array UT Platform for Customizing Dedicated and Automated NDT Applications

Small form factor, excellent signal-to-noise ratio (SNR), fast data throughput and an easy to integrate electronics are just some of the important aspects for automated phased array inspection systems. Furthermore, a software application programming interface (API) is crucial for creating a dedicated and simple software front end. This paper will present how a family of phased array ultrasonic modules can meet the demands of the most unique and innovative industrial and research based phased array applications.

A New Method for Driving 128CH Matrix Phased Array Probes with a Very Compact and High Performance Solution

As phased array UT continues to gain wide acceptance, matrix arrays are also becoming more common and easily attainable, creating a need for higher channel count instruments. The Nuclear and Power Generation industry has been a major influential force in driving NDT technology to its limits to further improve inspection speeds, while dealing with complex geometry. This paper will explore how pairing matrix arrays with new phased array (PA) technology opens doors to better inspections. A high performance PA instrument with faster data rates, a smaller form factor, and capability to adapt to specific applications will also be highlighted. Also, new system integration techniques for demanding applications are discussed.

New Customizable Phased Array UT Instrument Opens Door for Furthering Research and Better Industrial Implementation

Phased array UT as an inspection technique in itself continues to gain wide acceptance. However, there is much room for improvement in terms of implementation of Phased Array (PA) technology for every unique NDT application across several industries (e.g. oil and petroleum, nuclear and power generation, steel manufacturing, etc.). Having full control of the phased array instrument and customizing a software solution is necessary for more seamless and efficient inspections, from setting the PA parameters, collecting data and reporting, to the final analysis. NDT researchers and academics also need a flexible and open platform to be able to control various aspects of the phased array process. A high performance instrument with advanced PA features, faster data rates, a smaller form factor, and capability to adapt to specific applications, will be discussed.

Fast total focusing method for ultrasonic imaging

Synthetic aperture focusing technique (SAFT) and total focusing method (TFM) have become popular tools in the field of ultrasonic non destructive testing. In particular, they are employed for detection and characterization of flaws. From data acquired with a transducer array, those techniques aim at reconstructing an image of the inspected object from coherent summations. In this paper, we make a comparison between the standard technique and a migration approach. Using experimental data, we show that the developed approach is faster and offers a better signal to noise ratio than the standard total focusing method. Moreover, the migration is particularly effective for near-surface imaging where standard methods used to fail. On the other hand, the migration approach is only adapted to layered objects whereas the standard technique can fit complex geometries. The methods are tested on homogeneous pieces containing artificial flaws such as side drilled holes.

Fast Focusing Methods For Ultrasonic Imaging

This work deals with advanced and fast imaging techniques using phased array probes for non destructive evaluation or medical imaging. These methods employ a large amount of summations in order to focus at each pixel of the reconstruction image, which often represent a prohibitive computational cost. We present two acceleration methods, i.e. GPU computation and a migration approach. The GPU computing uses massively parallel computations. The migration approach works in the wavenumber domain and permits a significant improvement in terms of image quality. In this paper, we demonstrate the benefits of these techniques with experimental data captured from an aluminum block containing artificial flaws.

Total focusing method imaging for flaw characterization in homogeneous media

Phased array imaging using multi-element probes is an efficient technique to detect and characterize flaws in industrial components. In particular, the total focusing methods are advanced approaches that optimally focus at each point of the reconstruction zone. They generally outperform conventional imaging in terms of reconstruction quality and computational cost. They need all transmitter-receiver pair signals of an array of transducers. Then, the post-processing is performed by computing the proper propagation times at each reconstruction point and by applying coherent summations over all elements. A migration approach working in the wavenumber domain is analogous for total focusing. In this paper, we show experimental results of flaw characterization in homogeneous media using those total focusing methods. We demonstrate that the migration approach leads to a better signal to noise ratio and a better resolution for side drilled hole and horizontal slit reconstruction. On the other hand, the standard total focusing method achieves a better imaging of angled slits.

Full Matrix Capture with a Customizable Phased Array Instrument

In recent years, a technique known as Full-Matrix Capture (FMC) has gained some headway in the NDE community for phased array applications. It’s important to understand that FMC is the method that the instrumentation acquires the ultrasonic signals, but further post-processing is required in software to create a meaningful image for a particular application. Having a flexible software interface, small form factor, excellent signal-to-noise ratio per acquisition channel on a 64/64 or 128/128 phased array module with FMC capability proves beneficial in both industrial implementation and in further investigation of post-processing techniques. This paper will provide an example of imaging with a 5MHz linear phased array transducer with 128 elements using FMC and a popular post-processing algorithm known as Total-Focus Method (TFM).

New Customizable Phased Array UT Instrument Opens Door for Furthering Research and Better Industrial Implementation

Phased array UT as an inspection technique in itself continues to gain wide acceptance. However, there is much room for improvement in terms of implementation of Phased Array (PA) technology for every unique NDT application across several industries (e.g. oil and petroleum, nuclear and power generation, steel manufacturing, etc.). Having full control of the phased array instrument and customizing a software solution is necessary for more seamless and efficient inspections, from setting the PA parameters, collecting data and reporting, to the final analysis. NDT researchers and academics also need a flexible and open platform to be able to control various aspects of the phased array process. A high performance instrument with advanced PA features, faster data rates, a smaller form factor, and capability to adapt to specific applications, will be discussed.