Emissivity considerations in building thermography

Avdelidis, NP; Moropoulou, A

dc.contributor.author	Avdelidis, NP	en
dc.contributor.author	Moropoulou, A	en
dc.date.accessioned	2014-03-01T11:44:33Z
dc.date.available	2014-03-01T11:44:33Z
dc.date.issued	2003	en
dc.identifier.issn	0378-7788	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/37009
dc.subject	Buildings	en
dc.subject	Emittance	en
dc.subject	Infrared thermography	en
dc.subject	Surface condition	en
dc.subject	Temperature	en
dc.subject	Wavelength	en
dc.subject.classification	Construction & Building Technology	en
dc.subject.classification	Energy & Fuels	en
dc.subject.classification	Engineering, Civil	en
dc.subject.other	Atmospheric humidity	en
dc.subject.other	Cameras	en
dc.subject.other	Electromagnetic waves	en
dc.subject.other	Infrared radiation	en
dc.subject.other	Thermography (imaging)	en
dc.subject.other	Infrared cameras	en
dc.subject.other	Buildings	en
dc.title	Emissivity considerations in building thermography	en
heal.type	other	en
heal.identifier.primary	10.1016/S0378-7788(02)00210-4	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0378-7788(02)00210-4	en
heal.language	English	en
heal.publicationDate	2003	en
heal.abstract	In the last 25 years, there have been considerable efforts put into the use and development of infrared thermography on buildings and large structures. As a result, nowadays, there are systems that can be used effectively in outdoor and/or indoor building surveys; indication and monitoring of problems such as voids, detached areas, deposits of humidity, etc. However, the principal problem where infrared thermographic measurements are concerned is the emissivity - emittance of the material(s). Given that an infrared camera detects the radiation emitted by a material under investigation and renders this energy to a temperature - thermal image, the feature that describes the relation between the emitted radiation and the material's temperature, is termed as emissivity. Emissivity is actually a surface property that states the ability of the investigated material to emit energy. Correct emissivity values could provide valuable information concerning the interpretation of thermal images obtained from thermographic surveys. There is a considerable amount of work that has been published on emissivity of different materials and under various circumstances (i.e. temperature, surface condition, wavelength). In this work, a review on emissivity measurement techniques and the importance of emissivity values on building diagnostics was materialised. Furthermore, the emissivity of selected building materials were determined at a variety of temperatures, in the mid and long wavelength regions of the infrared spectrum, using different approaches and were discussed and explained in terms of the approach used, the wavelength and temperature effects, as well as the materials surface state. © 2002 Elsevier Science B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE SA	en
heal.journalName	Energy and Buildings	en
dc.identifier.doi	10.1016/S0378-7788(02)00210-4	en
dc.identifier.isi	ISI:000183587600004	en
dc.identifier.volume	35	en
dc.identifier.issue	7	en
dc.identifier.spage	663	en
dc.identifier.epage	667	en