Filtered thermal contrast based technique for testing of material by infrared thermography

• Autorzy: Gryś S.
• Języki publikacji: EN

Abstrakty

EN

A new kind of thermal contrast, called ''filtered contrast'' is presented, which allows detecting and characterizing material defects using active thermography under some assumptions on physical and thermal parameters of materials. In opposition to known definitions of the thermal contrast, knowledge about defect-free area is not necessary and this contrast is less sensitive to nonuniformity of heat disposal to the material surface. The measurements were performed on an experimental setup equipped with a ThermaCAM PM 595 infrared camera and frame grabber. The step heating was chosen as heat excitation. The results demonstrate usefulness of the 1D model of heat transfer used for determination of depth of subsurface defects. The influence of the parameter of the smoothing filter, required for filtered contrast implementation, thermal parameters of the tested material and defect on expanded uncertainty of determination of defect depth is also presented. Due to significant complexity of the model of heat transfer, the conditions for the "law of propagation of uncertainty" were not fulfilled and a numerical method, i.e., Monte Carlo simulation is applied for the propagation of distributions.

Słowa kluczowe

EN

active infrared thermography; thermal contrast; image segmentation; defect characterisation; uncertainty analysis

• Wydawca: Stowarzyszenie Elektryków Polskich ; Polska Akademia Nauk ; Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
• Czasopismo: Opto-Electronics Review
• Rocznik: 2011
• Tom: Vol. 19, No. 2
• Strony: 234--241
• Opis fizyczny: Bibliogr. 10 poz., il., wykr.

Twórcy

autor

Gryś S.

• Institute of Electronics and Control Systems, Częstochowa University of Technology, 17 Armii Krajowej Ave., 42-200 Częstochowa, Poland,

Bibliografia

• [1] X. Maldague, Theory and Practice of Infrared Technology for Nondestructive Testing, John Wiley & Sons, Inc., New York, 2001.
• [2] S. Gryś, W. Minkina, and S. Chudzik: Detection of subsurface defects on the basis of thermogram analysis. Proc. 17th Symp. on Modelling and Simulation of Measuring Systems, Krynica Górska, Poland, 27-35, 2009. (in Polish)
• [3] J.C. Murphy, L.C. Aamodt, and J.W. Maclachlan Spicer: Principles of photothermal detection in solids. Principles and Perspectives of Photothermal and Photoacoustic Phenomena, pp. 41-94, edited by A. Mandelis, Elsevier, New York, 1992.
• [4] W. Minkina and S. Dudzik, Infrared Thermography - Errors and Uncertainties, John Wiley & Sons Ltd, Chichester, 2009.
• [5] R. Heriansyah and S.A.R. Abu-Bakar: Defect detection in thermal image for nondestructive evaluation of petrochemical equipments. NDT&E International 42, 729-740, 2009.
• [6] S. Dudzik: A simple method for defect area detection using active thermography. Opto-Electron. Rev. 17, 338-344, 2009.
• [7] N. Otsu: A threshold selection method from grey-level histograms. IEEE T. Syst. Man Cyb. 9, 62-66, 1979.
• [8] R. Haralick and L. Shapiro, Computer and Robot Vision, Vol. I, Addison-Wesley, pp. 28-48, 1992.
• [9] Guide to the Expression of Uncertainty in Measurement. Supplement 1. Numerical Methods for the Propagation of Distributions, Joint Committee for Guides in Metrology, 2004.
• [10] Evaluation of Measurement Data - Guide to the Expression of Uncertainty in Measurement, [GUM 1995 with minor corrections], JCGM, (100) 2008.