2-D near-field SAR non-destructive testing of rebars in a concrete wall

In this paper, a new ultrasonic phased array full focus imaging method based on oblique incidence is proposed to solve the problem of the non-destructive testing of the internal defects in the GIS (gas insulated switchgear) shell welds. By using wedge coupling, the measured weld is far away from the near-field range of the transducer, and the detection angle range can be increased by changing the propagation direction of the acoustic beam. Based on Snell's law, the propagation characteristics of the ultrasonic wave in the interface are studied. On the basis of the conventional ultrasonic array matrix and the full focus imaging algorithm, by introducing the energy attenuation calibration coefficient of the acoustic wave propagation through the wedge, the correction amplitude of the specific focus point p(x, z) is obtained, The non-destructive testing of weld defects of GIS shell in the spot is carried out, and the test results show that the qualitative and quantitative detection of the weld defects can be well realized by using this method.

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Detecting damages in outdoor non-ceramic insulators using near field microwave non-destructive testing

2009 IEEE Electrical Insulation Conference ◽

10.1109/eic.2009.5166325 ◽

2009 ◽

Cited By ~ 1

Author(s):

Nasser Qaddoumi ◽

Ayman H. El-Hag ◽

Mohamed Al Hosani ◽

Ibrahim Al Mansouri ◽

Hamad Al Ghufli

Keyword(s):

Near Field ◽

Non Destructive Testing ◽

Destructive Testing ◽

Ceramic Insulators ◽

Non Destructive

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OPTO-TECHNICAL MONITORING – A STANDARDIZED METHODOLOGY TO ASSESS THE TREATMENT OF HISTORICAL STONE SURFACES

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-2-945-2018 ◽

2018 ◽

Vol XLII-2 ◽

pp. 945-952

Author(s):

M. Rahrig ◽

R. Drewello ◽

A. Lazzeri

Keyword(s):

Near Field ◽

Three Dimensional ◽

Non Destructive Testing ◽

New Materials ◽

Testing Methods ◽

Destructive Testing ◽

Monitoring Method ◽

Horizon 2020 ◽

Research And Innovation ◽

Non Destructive

Monitoring is an essential requirement for the planning, assessment and evaluation of conservation measures. It should be based on a standardized and reproducible observation of the historical surface. For many areas and materials suitable methods for long-term monitoring already exist. But hardly any non-destructive testing methods have been used to test new materials for conservation of damaged stone surfaces. The Nano-Cathedral project, funded by the European Union's Horizon 2020 research and innovation program, is developing new materials and technologies for preserving damaged stone surfaces of built heritage. The prototypes developed are adjusted to the needs and problems of a total of six major cultural monuments in Europe. In addition to the testing of the materials under controlled laboratory conditions, the products have been applied to trial areas on the original stone surfaces. For a location-independent standardized assessment of surface changes of the entire trial areas a monitoring method based on opto-technical, non-contact and non-destructive testing methods has been developed. This method involves a three-dimensional measurement of the surface topography using Structured-Light-Scanning and the analysis of the surfaces in different light ranges using high resolution VIS photography, as well as UV-A-fluorescence photography and reflected near-field IR photography.<br> The paper will show the workflow of this methodology, including a detailed description of the equipment used data processing and the advantages for monitoring highly valuable stone surfaces. Alongside the theoretical discussion, the results of two measuring campaigns on trial areas of the Nano-Cathedral project will be shown.

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