Resumen: Early detection of cracks is a challenging task to prevent failures in working structures. In the last decades the ‘flying spot’ method, based on heating the sample with a moving laser spot and detecting the surface temperature with an infrared detector, has been developed to detect cracks in a fast manner. The aim of this work is to measure the width of an infinite vertical crack using lock-in thermography. An analytical solution for the surface temperature of a sample containing such a crack when the surface is illuminated by a modulated laser beam focused at a fixed spot close to the crack is obtained. Measurements on samples containing calibrated cracks have been performed using an infrared camera. A least square fit of the amplitude and phase of the surface temperature is used to retrieve the thickness of the crack. A very good agreement between the nominal and retrieved thicknesses of fissure is found, even for widths down to 1 µm, confirming the validity of the model. Idioma: Inglés DOI: 10.1088/0957-0233/25/11/115601 Año: 2014 Publicado en: MEASUREMENT SCIENCE & TECHNOLOGY 25, 11 (2014), 115601 [11 pp.] ISSN: 0957-0233 Factor impacto JCR: 1.433 (2014) Categ. JCR: INSTRUMENTS & INSTRUMENTATION rank: 25 / 56 = 0.446 (2014) - Q2 - T2 Categ. JCR: ENGINEERING, MULTIDISCIPLINARY rank: 23 / 85 = 0.271 (2014) - Q2 - T1 Tipo y forma: Article (PostPrint) Área (Departamento): Área Matemática Aplicada (Dpto. Matemática Aplicada) Área (Departamento): Proy. investigación HMA (Dpto. Matemática Aplicada)