Three-dimensional (3D) imaging and infrared (IR) thermography are powerful tools in many areas in engineering and sciences. Their joint use is of great interest in the buildings sector, allowing inspection and non-destructive testing of elements as well as an evaluation of the energy efficiency. When dealing with large and complex structures, as buildings (particularly historical) generally are, 3D thermography inspection is enhanced by Unmanned Aerial Vehicles (UAV—also known as drones). The aim of this paper is to propose a simple and cost-effective system for aerial 3D thermography of buildings. Special attention is thus payed to instrument and reconstruction software choice. After a very brief introduction to IR thermography for buildings and 3D thermography, the system is described. Some experimental results are given to validate the proposal.

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In the complex procedure for the conservation of a work of art, the effective monitoring of the surface treatment is an important step in order to establish a conservation protocol. The evaluation of the effects of the cleaning requires the inspection of the outermost layer with complementary diagnostic techniques to obtain information on both materials and surface morphology. In this interdisciplinary work, a custom optical micro-profilometry device based on laser conoscopic holography was used for testing the performance of different mechanical procedures for the cleaning of silver alloy objects. Tarnishing is the main alteration phenomenon for silver alloy artworks. Even if such modification does not affect the long-term preservation of the objects, it heavily influences aesthetical features, making the removal of tarnishing one of the most important conservation treatments of the case. The mechanical cleaning procedure based on abrasive powders suspended in a liquid matrix is of widespread use. Recently, a novel dry cleaning procedure based on the use of erasers was proposed as alternative method and tested for both the efficacy of tarnishing removal and effects on the surface appearance using optical microscopy and scanning electron microscopy. However, the employed laboratory techniques cannot provide an objective measure of the roughness at micrometric scale over the sample. In this work, the effects on the surface structure of traditional and innovative silver treatments was investigated with multiscale profilometry, using scanning conoscopic holography and atomic-force microscopy. 3D surface metrology was carried out using standard areal amplitude parameters and a multiscale approach. Preliminary results are presented, addressing two aspects: 1) the validation of laser optical micro-profilometry for the diagnostics of silver objects, which are challenging due to the highly specular surface; 2) the validation of the dry-cleaning treatment based on rubbers, by adding to the previous study the complimentary analysis of the micro-surface. The results obtained on silver mockups confirm that the proposed dry cleaning methods produce surface variations less or similar to traditional methods. The optical micro-profilometry results are of particular significance since this technique is portable with wide field capability, thus allowing an in-situ use and a real monitoring of actual artwork surfaces.

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