External radiation as element of improvement infrared thermography measurements

Abstract

Infrared thermography is a very versatile non destructive technique which among other uses, can be applied to the study of moisture in buildings. However, this particular application can present some problems strictly related to the characteristics of the thermocamera device. In this case the available equipment works in the IR range of 2.5 to 5.6 μm. In this part of the spectrum, there exists a small and not very intense band of emission of the water molecules (approximately centered at 2.7 μm), in such a way that detection can be difficult through thermovision. In the present paper, a complementary technique to the IR thermography being able of favouring the emission of water on the mentioned band, has been developed. It enhances the capacity of detection of the instrument. Likewise, the process which takes place in the material has been numerically modelled.