Infrared detection of moist areas in monumental buildings based on thermal inertia analysis

Ermanno G. Grinzato; Andrea Mazzoldi

doi:10.1117/12.46425

1 March 1991 Infrared detection of moist areas in monumental buildings based on thermal inertia analysis

Ermanno G. Grinzato, Andrea Mazzoldi

Proceedings Volume 1467, Thermosense XIII; (1991) https://doi.org/10.1117/12.46425
Event: Orlando '91, 1991, Orlando, FL, United States

Abstract

This paper presents a technique to detect the moisture conditions of walls supporting frescoes in order to detach its in case and to understand causes of the surface wetting. An important feature of the testing procedure is to be nondestructive and appropriate to analyze large surfaces as it is based on thermographic image processing. The goal is to classify the wall surface on the basis of its moisture condition. We choose the thermal inertia as the most suitable parameter for this purpose, because the heat capacity of a porous body increases to a great extent by varying its water content. The test works modifying the wall inner thermal conditions and detecting temperature variations of the fresco, in time and space domain. For this purpose a convective thermal flux is uniformly applied to the surface while an infrared camera views it. In such a way temperature gradients appear, whose maximum directional variation curves are used to segment the surface and the mean temperature time difference is used to label each area. The key point of the proposed procedure is the freedom from the knowledge of the wall composition and its thermal and hydrologic dynamic status, depending on weather history. Other topics as the environmental radiometric reflection and emission, the 'Narcissus effect' in thermograms mosaic composition and the perspective distortions are considered. Experimental results on a XVI century church at Padua (Italy) are presented.

Citation Download Citation

Ermanno G. Grinzato and Andrea Mazzoldi "Infrared detection of moist areas in monumental buildings based on thermal inertia analysis", Proc. SPIE 1467, Thermosense XIII, (1 March 1991); https://doi.org/10.1117/12.46425

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available