| ABSTRACT: | TEMPERATURE MONITORS WORKS OF ART HEALTH AS HUMAN BEINGS
Ermanno Grinzato
CNR, Padova, Italy
NDT/NDE is an indirect measurement and temperature is a perfect informative parameter when shallow
defects are investigated. Temperature monitors an incredible number of different phenomena because finally
any physical and chemical process involves heat. A large literature is growing about thermal NDT/TNDE.
Progress of IR thermography makes this method, alone or combined with others, a suitable tool. Today,
highly resolute equipments or much cheaper ones are applied in combination either with the simple
examination of thermal images or sophisticated data reduction algorithms. Particularly, works of art are
more and more issued for economic and cultural purposes. For this application the concept of “defect” is
much broader than in industry, including both object’s knowledge and its status monitoring. In fact, usually
the real history of precious items was lost along centuries and the NDT target becomes the discovery of
hidden information. For instance, the bricks pattern below a plaster layer shows the building time of
different parts, but a fast, reliable and pictorial result is needed. Furthermore, the surface temperature and
moisture is a key factor for the comfort of people working inside a renewed historical building. A review of
different cases study applied to frescos, ceramics, wood paintings, heritage buildings etc. shows as
TNDT/TNDE when applied to works of art is particularly difficult. The main problems occur because of
strong limitations in the object treatment, sampling is avoided and no references are available. Hence, in
many cases a particular equipment and procedures must be arranged. A fundamental role is played by
mathematical simulation of the thermal process, but generally thermal properties are themselves unknown.
Therefore, the thermal diffusivity and effusivity measurement could be the goal of TNDE. It is
demonstrated, as these parameters mapping is an effective investigation way.
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