Estimation of the area and depth of buried heat sources: an approach to characterize defects in inductive and ultrasound excited thermography

Arantza Mendioroz; Agustín Salazar; Paul Lasserre; Beate Oswald-Tranta; Christoph Tuschl

doi:10.1117/12.2663135

12 June 2023 Estimation of the area and depth of buried heat sources: an approach to characterize defects in inductive and ultrasound excited thermography

Arantza Mendioroz, Agustín Salazar, Paul Lasserre, Beate Oswald-Tranta, Christoph Tuschl

Author Affiliations +

Proceedings Volume 12536, Thermosense: Thermal Infrared Applications XLV; 125360M (2023) https://doi.org/10.1117/12.2663135
Event: SPIE Defense + Commercial Sensing, 2023, Orlando, Florida, United States

Abstract

We address the characterization of defects that behave as heat sources in nondestructive thermographic techniques. First, we consider tilted heat sources of rectangular shape. We calculate the evolution of the surface temperature distribution generated in a short excitation. For the characterization, we make use of the thermogram obtained at the end of the excitation and the temperature evolution at the center of the early heated region. A sensitivity analysis indicates that the optimum excitation duration corresponds to a thermal diffusion length similar to the depth of the deepest end of the heat source. By fitting synthetic data with added noise, we analyze the influence of the signal to noise ratio and the inclination of the heat source on the fitted parameters. Inductive thermography experiments carried out on insulating samples with embedded Cu slabs confirm the ability of the method to characterize tilted heat sources and indicate that the penetration is the most elusive parameter. In the second part, we present a methodology to deal with horizontal heat sources of unknown geometry. We average the thermogram obtained at the end of the excitation in circumferences concentric with the center of the heated region. This averaged radial profile, together with the temperature evolution at the center of the heated region is fitted to a circular heat source model. Fittings of experimental data taken on samples with horizontal rectangular Cu slabs allow determining the area with accuracy better than 20% and the depth with 10%.

Conference Presentation

Citation Download Citation

Arantza Mendioroz, Agustín Salazar, Paul Lasserre, Beate Oswald-Tranta, and Christoph Tuschl "Estimation of the area and depth of buried heat sources: an approach to characterize defects in inductive and ultrasound excited thermography", Proc. SPIE 12536, Thermosense: Thermal Infrared Applications XLV, 125360M (12 June 2023); https://doi.org/10.1117/12.2663135

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available