P1 - Selection of suitable excitation and recording conditions for active lock-in thermography with the help of parameter studies
- Event
- AMA Conferences 2017
2017-05-30 - 2017-06-01
Nürnberg, Germany - Band
- Proceedings IRS² 2017
- Chapter
- IP - Poster Session
- Author(s)
- G. Schober, C. Kolb, S. Kremling, M. Werner - SKZ – German Plastics Center, Würzburg (Germany), M. Fink - Julius-Maximilians-Universität, Würzburg (Germany)
- Pages
- 809 - 812
- DOI
- 10.5162/irs2017/iP1
- ISBN
- 978-3-9816876-4-4
- Price
- free
Abstract
In the field of non-destructive testing (NDT), active lock-in thermography is state of the art. Thereby, the test object is externally excited with different modulated thermal sources. The thermal excitation may be induced optically by lamps, by ultrasonic waves or in case of conductive materials also by eddy currents. Lock-in thermography is frequency-selective, e.g. it responds only to temperature changes at the specific excitation frequency. In theory, the phase image obtained from Fourier analysis shows thermal structures below the surface without influences of inhomogeneities from excitation. However, in reality there are significant influences of several parameters on phase image quality as well as the acquisition and evaluation time and the needed memory capacity. Here, we present a parameter study of relevant optical excitation properties to increase the probability of detection of flaws.