&lt;title&gt;Phase-sensitive modulation thermography and its applications for NDE&lt;/title&gt;

Wu, D.; Salerno, A.; Schoenbach, Bernd; Hallin, Hans; Busse, G.

doi:10.1117/12.271641

Cited by 33 publications

(15 citation statements)

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“…2). Dynamic thermography is often named pulse or lock-in thermography [11]- [15]. The example of such measurements could be the research of semiconductor and other electronic structures, where the flow of electric current is the source of thermal effects.…”

Section: Thermal Pulse Methodsmentioning

confidence: 99%

Thermovision and ground penetrating radar for investigation of architectural decorations – potential and limitations

Cupa¹,

Felczak²,

Kurkiewicz³

et al. 2012

Proceedings of the 2012 International Conference on Quantitative InfraRed Thermography

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In the Institute for the Study, Conservation and Restoration of Cultural Property, Nicolaus Copernicus University, Torun, in recent years research is conducted on the application of non-destructive methods for diagnosis of historic monuments. The research presented below is the first in Poland attempt of systematic application of thermovision and radar methods for the analysis of complex structures in mural paintings.The thermographic examination was performed on a laboratory model of architectural decoration, using thermographic cameras working in the near (NIR 0.8-1.5 µm) and far-infrared (LWIR 7-14 µm) and ground penetrating radar (GPR), equipped with a scanning aerial 0,9 and 2 GHz.The model of damaged and treated polychrome plasters was created specifically for the research work and it was prepared to resemble the situations occurring in historic structures.

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Section: Thermal Pulse Methodsmentioning

confidence: 99%

Thermovision and ground penetrating radar for investigation of architectural decorations – potential and limitations

Cupa¹,

Felczak²,

Kurkiewicz³

et al. 2012

Proceedings of the 2012 International Conference on Quantitative InfraRed Thermography

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“…Unlike pulse thermography, both step heating thermography and modulated thermography use heat sources with moderate intensity, which can avoid ablation damage to the tested surface. Researchers have found modulated thermography to be effective in detecting deeply buried defects in both metallic and non-metallic materials, but the method requires the appropriate heat source excitation frequency to detect defects at certain depths [13,14,15]. To overcome excitation frequency limitations in modulated thermography, Mulaveesala developed frequency modulated thermography-a kind of thermographic method with viable excitation periods.…”

Section: Introductionmentioning

confidence: 99%

Comparison of step heating and modulated frequency thermography for detecting bubble defects in colored acrylic glass

Wang

Hsieh

2015

SPIE Proceedings

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Step heating thermography and modulated frequency thermography are two commonly used inspection methods. This research compares active step heating thermography and modulated frequency thermography for use in detecting defects with diameters of 1.98 mm to 6 mm buried at depths of 1.5 to 4 mm beneath sample surfaces. Experiments were conducted using colored acrylic samples.Step heating thermography can detect shallowly buried defects as early as 4 seconds after heating. Also, lengthening heating time allows step heating thermography to reveal differences between defects of 4 to 6 mm in diameter buried 1.5 mm to 4 mm beneath glass surface. Modulated frequency thermography provides a higher signal-to-noise ratio of 1.3 for smaller defects. Thus it can be used to detect defects with diameters as small as 1.98 mm buried 4 mm beneath the glass surface. However, this level of detection requires phase frequency to be lowered by an order of 10 −3 . An open problem is to develop a systematic method and/or heuristics for determining the appropriate frequency for different defect types.

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“…Moreover, materials which consist of various thermal conductivities may result in poor image contrast because of its complicated thermal propagation. Thus, lock-in method has been employed to infrared thermography to increase its detection performance [11][12][13][14][15][16]. Lock-in thermography technique commonly uses a heating device or an ultrasonic transducer as a periodical excitation source and the calculated amplitude and phase of measured thermal signal shows a defect of materials such as the size and depth of the damage.…”

Section: Introductionmentioning

confidence: 99%

NDE of Low-Velocity Impact Damage in GFRP Using Infrared Thermography Techniques

Kim¹,

Lee²,

Hur³

et al. 2015

Journal of the Korean Society for Nondestructive Testing

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In this study, low-velocity impact damage (LVID) in glass fiber reinforced plastic (GFRP) was investigated using pulse thermography (PT) and lock-in thermography (LIT) techniques. The main objective of this study was to evaluate the detection performance of each technique for LVID in GFRP. Unidirectional and cross-ply GFRPs were prepared with four energy levels using a drop weight impact machine and they were inspected from the impact side, which may be common in actual service conditions. When the impacted side was used for both inspection and thermal loading, results showed that the suggested techniques were able to identify the LVID which is barely visible to the naked eye. However, they also include limitations that depend on the GFRP thickness at the location of the delamination produced by the lowest impact energy of five joule.

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<title>Phase-sensitive modulation thermography and its applications for NDE</title>

Cited by 33 publications

References 0 publications

Thermovision and ground penetrating radar for investigation of architectural decorations – potential and limitations

Thermovision and ground penetrating radar for investigation of architectural decorations – potential and limitations

Comparison of step heating and modulated frequency thermography for detecting bubble defects in colored acrylic glass

NDE of Low-Velocity Impact Damage in GFRP Using Infrared Thermography Techniques

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