Absorption coefficient dispersion in flash thermography of semitransparent solids
- Pulse and flash thermography are experimental techniques which are widely used in the field of non-destructive testing for materials characterization and defect detection. We recently showed that it is possible to determine quantitatively the thickness of semitransparent polymeric solids by fitting of results of an analytical model to experimental flash thermography data, for both transmission and reflection configuration. However, depending on the chosen experimental configuration, different effective optical absorption coefficients had to be used in the model to properly fit the respective experimental data, although the material was always the same. Here, we show that this effect can be explained by the wavelength dependency of the absorption coefficient of the sample material if a polychromatic light source, such as a flash lamp, is used. We present an extension of the analytical model to describe the decay of the heating irradiance by two instead of only one effective absorptionPulse and flash thermography are experimental techniques which are widely used in the field of non-destructive testing for materials characterization and defect detection. We recently showed that it is possible to determine quantitatively the thickness of semitransparent polymeric solids by fitting of results of an analytical model to experimental flash thermography data, for both transmission and reflection configuration. However, depending on the chosen experimental configuration, different effective optical absorption coefficients had to be used in the model to properly fit the respective experimental data, although the material was always the same. Here, we show that this effect can be explained by the wavelength dependency of the absorption coefficient of the sample material if a polychromatic light source, such as a flash lamp, is used. We present an extension of the analytical model to describe the decay of the heating irradiance by two instead of only one effective absorption coefficient, greatly extending its applicability. We show that using this extended model, the experimental results from both measurement configurations and for different sample thicknesses can be fitted by a single set of parameters. Additionally, the deviations between experimental and modeled surface temperatures are reduced compared to a single optimized effective absorption coefficient.…
Autor*innen: | Simon AltenburgORCiD, Raphael Bernegger, Rainer KrankenhagenORCiD |
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Dokumenttyp: | Zeitschriftenartikel |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | International Journal of Thermophysics |
Jahr der Erstveröffentlichung: | 2018 |
Organisationseinheit der BAM: | 8 Zerstörungsfreie Prüfung |
8 Zerstörungsfreie Prüfung / 8.0 Abteilungsleitung und andere | |
Verlag: | Springer Nature |
Jahrgang/Band: | 40 |
Ausgabe/Heft: | 1 |
Erste Seite: | 13, 1 |
Letzte Seite: | 13 |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurbau | |
Freie Schlagwörter: | Absorptance; Dispersion; Flash thermography; Infrared thermography; NDT; Semitransparency |
Themenfelder/Aktivitätsfelder der BAM: | Chemie und Prozesstechnik |
Infrastruktur | |
Veranstaltung: | 19th International Conference on Photoacoustic and Photothermal Phenomena |
Veranstaltungsort: | Bilbao, Spain |
DOI: | 10.1007/s10765-018-2474-0 |
ISSN: | 0195-928X |
ISSN: | 1572-9567 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 21.12.2018 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 04.01.2019 |