Analyzing the Differences Between TOFD and Phased Array

2021-12-04

At present, TOFD technology is the most widely used nondestructive testing method in China, and it has already yielded countless successful applications across various industrial sectors. As an ultrasonic imaging technique, TOFD employs a single-transmit–single-receive probe configuration with a specified interprobe spacing, giving it significant advantages in the inspection of thick plates for butt joints, circumferential welds, and longitudinal seams with diameters greater than 500 mm. However, this technique also has certain limitations—for instance, it struggles to effectively inspect structural components with complex geometries and to eliminate detection blind spots in welds. To date, ultrasonic phased-array technology has been developed in China for 20 years, and in its early stages

A Brief Discussion on the Development and Application of PAUT Testing Technology

2021-11-20

Phased-array ultrasonics (PA) is an ultrasonic inspection and imaging technique that, based on a predefined focusing law, applies different time delays (or voltage levels) to individual elements of an array probe during sound-wave transmission or reception, thereby achieving beamforming to enable the steering, deflection, and focusing of the inspection beam. This technology boasts high defect detection rates, accurate quantification, flexible process design and implementation, rapid on-site data acquisition, comprehensive preservation of raw recorded data with multi-view imaging display, and minimal influence of human factors on inspection results—making it an environmentally friendly, green technology free from ionizing radiation and chemical contamination. Phased-array ultrasonic technology has been applied in medical imaging and industrial nondestructive testing. Common applications include noninvasive cardiac examinations and the detection of flaws in manufactured materials, such as welds. Single-element (non-phased-array) probes, technically referred to as single-chip probes, emit beams in a fixed direction. To inspect or examine large volumes of material, conventional probes must be physically scanned—moved or rotated—to sweep the beam across the area of interest. In contrast, phased-array probes can focus their beams and perform electronic scanning without moving the probe itself. The beam is controllable because a phased-array probe consists of multiple small elements, each of which can be individually pulsed at precisely calculated moments by the control system. The term “phased” refers to timing, while “array” denotes multiple elements. Phased-array ultrasonic testing is grounded in wave physics and also finds applications in optics and electromagnetic antenna systems. A PA probe comprises numerous small ultrasonic transducers, each capable of independent pulsing. By adjusting the timing—for example, by gradually delaying the pulses from each transducer along the array—a constructive interference pattern is established, resulting in the emission of a quasi-planar ultrasonic beam at a predetermined angle through progressive time delays. In other words, by varying these progressive time delays, the beam can be electronically steered. The beam can sweep across the inspected tissue or object like a searchlight, and data from multiple beams are combined to form a visual image that displays cross-sectional slices through the object. Phased-array techniques are widely used for nondestructive testing in various industrial sectors, including construction, piping, and power generation. This method is an advanced NDT approach for detecting discontinuities—such as cracks or fissures—and thereby assessing component quality. Because parameters such as beam angle and focal length can be controlled, the method is highly effective in both defect detection and testing speed. In addition to identifying defects in components, phased arrays can also be used in conjunction with corrosion testing for wall-thickness measurement. Phased-array technology is primarily employed in the following industrial applications: 1. Weld inspection Example 1: Ultrasonic phased-array systems for detecting weld defects in small-diameter pipes: A quick-detach scanning device enables both single-sided and double-sided phased-array inspections, while self-focusing probes enhance detection sensitivity and resolution. For welds with wall thicknesses of 8 mm or less, separate settings for the second and third echoes—with differing sensitivities—can be used during inspection. Example 2: Ultrasonic phased-array systems for detecting defects in fillet welds at pipe-to-pipe joints. Traditional industrial phased-array methods lack geometric-reflection-signal correction technology. Given the vast diversity of workpiece geometries and material types in industrial settings, it has long been difficult to generate corresponding images based on workpiece thickness and structural features, leading to significant challenges in data analysis that have yet to be effectively resolved. The lsonic series of ultrasonic phased-array inspection systems manufactured by Israel’s Sonotron NDT uses actual workpiece thickness and structural shape as the processing platform, superimposing multiple echo images at their true locations to eliminate spurious signals and ensure that scan images accurately reflect real-world positions. 2. Thickness measurement 3. Corrosion imaging and composite-material inspection 4. PAUT verification/demonstration blocks 5. Locomotive and rolling-stock inspection (wheels and axles) Of course, compared with conventional ultrasonic testing systems, PA instruments and probes are more complex and expensive. Moreover, in the industry, PA technicians require more experience and training than conventional UT technicians; personnel engaged in PAUT testing must hold NDT qualification certificates issued or recognized by CCS before they can perform inspections at the corresponding qualification level. In summary, phased-array ultrasonics currently plays a vital role in production-quality inspection, equipment utilization, and safety-performance assessment, having been adopted across diverse industrial sectors such as railways, aerospace, petroleum, and nuclear power plants. Its broad application prospects will drive its further development toward real-time, intelligent, and portable solutions.

In-depth Analysis of TOFD Nondestructive Testing Technology

2021-11-13

Unveiling TOFD Nondestructive Testing Technology In recent years, TOFD nondestructive testing has become a hot topic in Western countries and has been vigorously promoted and applied, to the point where it is increasingly seen as on par with radiographic testing. Given the current trajectory of TOFD technology development and adoption, coupled with the growing expertise of NDT personnel in this field, it is widely believed that TOFD has great potential to eventually replace radiographic testing—a technique that carries certain risks and demands stringent protective measures. At present, however, TOFD technology and equipment are still relatively scarce in China, and many people’s understanding of it remains limited to its use in inspecting thick-walled pressure vessels. Today, let me take you on a journey into the world of TOFD.

Application of New Nondestructive Testing Technologies in Shipbuilding Inspection

2021-11-05

With the development of the economy and technology, China’s shipbuilding industry has been propelled forward and continuously advanced. Today, nondestructive testing (NDT) plays an increasingly significant role throughout the design, production, operation, and repair of ships, serving as a crucial guarantee of construction quality. Therefore, it is highly necessary to establish a comprehensive NDT program during the shipbuilding process. 1. Current Status of NDT Development in China In recent years, as China’s national technological and economic levels have steadily risen, NDT has also experienced leapfrog development. The enhancement of overall national strength has facilitated the advancement of NDT.

In which industrial sectors are nondestructive testing devices used?

2021-10-28

Nondestructive testing is a testing method that examines the surface and internal quality of inspected components without damaging the workpiece or the raw material in its service condition. The objectives of nondestructive testing are to improve manufacturing processes, reduce manufacturing costs, enhance product reliability, and ensure the safe operation of equipment.

Ultrasonic Testing of Large Cast and Forged Components

2021-10-16

Ultrasonic testing (UT) is an inspection method used for quality control in the metallurgical industry and the equipment manufacturing sector. A major advantage of UT is its strong capability to detect planar defects such as cracks.

Comparison of Requirements for Sensitivity Verification in Color-Developed Penetrant Testing According to Domestic and International Standards

2021-09-04

Penetrant testing, as one of the five conventional nondestructive testing methods, is widely used in the fields of pressure-containing special equipment and civil nuclear safety equipment.

Phased Array Ultrasonic Testing of Lap Corner Welds in In-Service Pressure Vessels

2021-08-27

Welded joints in pressure vessels are classified into five categories: A, B, C, D, and E. Among these, the joint connecting non-pressure-bearing components to pressure-bearing components is designated as an E-class welded joint. E-class welded joints are commonly found in such structures as welds between backing plates and vessel walls, connections between nozzles with reinforcing rings and the shell, and connections between skirt supports and heads, typically in the form of lap fillet welds. During the start-up, shutdown, and operation of in-service pressure vessels, transient temperature changes and fluctuations in operating conditions can induce substantial stresses. When lap fillet welds contain welding defects such as lack of fusion or incomplete penetration, these defects can lead to stress concentrations, which in turn may cause damage to the base metal of the vessel shell.

< 1...5 6 7...9 > proceed page

Address: Room 104, Building 9, Futong Intelligent Manufacturing Industrial Park, Jinye 1st Road, Yiyang County, Luoyang City, Henan Province

Phone:+86-379-66915081 +86-379-66915005

Email:lywcjc@lywcjc.cn

Fax:+86-379-66919852

Website:www.lywcjc.cn

WeChat

Yu Public Security Bureau Filing No. 41030602000129

COOKIES

Our website uses cookies and similar technologies to personalize the advertising shown to you and to help you get the best experience on our website. For more information, see our Privacy & Cookie Policy

COOKIES

required

These cookies are necessary for basic functions such as payment. Standard cookies cannot be turned off and do not store any of your information.

analyze

These cookies collect information, such as how many people are using our site or which pages are popular, to help us improve the customer experience. Turning these cookies off will mean we can't collect information to improve your experience.

Feature

These cookies enable the website to provide enhanced functionality and personalization. They may be set by us or by third-party providers whose services we have added to our pages. If you do not allow these cookies, some or all of these services may not function properly.

advertise

These cookies help us understand what you are interested in so that we can show you relevant advertising on other websites. Turning these cookies off will mean we are unable to show you any personalized advertising.