http://mdpi.com/journal/sensors/special_issues/sensors-for-art-diagnostic/ Science and technology have become fundamental tools for the preservation of Cultural Heritage. New technologies are developed and used for documentation, study and preservation of works of art, archaeological sites, historical buildings and other relevant objects of cultural interest. This research field has been constantly growing in recent years and now involves many of the disciplinary areas of modern science. The major aim of scientific investigations in art diagnostic is the acquisition and safe storage of reliable information on the studied object. The simple storage of data is in itself a very important tool for preservation. The ideal case would be the acquisition of a complete database containing all the relevant information on the state of the object to be preserved, and very often we cannot even guess on what information will be relevant in years to come. In modern measuring systems, the measurement scheme often used is the chain “source-object-sensor-computer” for active systems and “object-sensor-computer” for passive ones. Where data are to be recorded, to gather information on a studied object, sensors plays a fundamental role. For instance, the availability of imaging sensors like the CCD opened the way to a number of very important applications in the optical analysis of artworks. The coupling of sensors with digital systems has been another major breakthrough and it is now mandatory both in laboratory and field use. Diagnostic and restoration projects of masterpieces frequently use many different techniques, requiring the use of many kinds of different sensors. Monitoring the environment conditions of sites, like museums, buildings or archaeological sites, requires wide nets of different sensing devices. The field covered by this special issue is then huge, due to the vastness of the type of information that can be acquired on cultural heritage objects. Contributions are expected in the fields of sensors for physical measurements, for chemical and biological analyses, for environmental monitoring, and for other fields of interest to cultural heritage diagnostics. http://mdpi.com/1424-8220/8/12/8401/ Environmental control in galleries and museums is a necessity and is informed by the knowledge of ongoing processes of deterioration which can threaten the integrity and stability of artworks. Invisible dimensional changes in many works of art occur following environmental fluctuations as materials respond to the changes in humidity and temperature. The constant influence of dimensional changes usually remains invisible until displacement generates visible deterioration and irreversible damage. This paper exploits fully non contact coherent interferometry in a sequential masking procedure for visualising and studying surface deformation which is the direct effect of dimensional alterations induced by humidity changes. Surface deformation during dimensional displacements of constituent materials may occur on any artwork within an unstable environment. In this context, the presented research study explores the diagnostic potential of fully non contact sensors for the direct structural assessment of environmental effects as they occur in real time on works of art. The method is employed to characterise material responses, complementing and improving understanding of material behaviour in unstable environments. http://mdpi.com/1424-8220/8/12/8401/ Thu, 18 Dec 2008 00:00:00 CET Sensors 2008-12-18 8 12 Article 8401 8422 1424-8220 Fully-Non-Contact Masking-Based Holography Inspection on Dimensionally Responsive Artwork Materials 2008-12-18 doi: 10.3390/s8128401 Vivi Tornari Eirini Bernikola Austin Nevin Eleni Kouloumpi Michalis Doulgeridis Costas Fotakis http://mdpi.com/1424-8220/8/12/8378/ The advanced characteristics of synchrotron light has led in recent years to the development of a series of new experimental techniques to investigate chemical and physical properties on a microscopic scale. Although originally developed for materials science and biomedical research, such techniques find increasing applications in other domains – and could be quite useful for the study and conservation of cultural heritage. Specifically, they can nondestructively provide detailed chemical composition information that can be useful for the identification of specimens, for the discovery of historical links based on the sources of chemical raw materials and on chemical processes, for the analysis of damage, their causes and remedies and for many other issues. Likewise, morphological and structural information on a microscopic scale is useful for the identification, study and preservation of many different cultural and historical specimens. We concentrate here on two classes of techniques: in the first case, photoemission spectromicroscopy. This is the result of the advanced evolution of photoemission techniques like ESCA (Electron Microscopy for Chemical Analysis). By combining high lateral resolution to spectroscopy, photoemission spectromicroscopy can deliver fine chemical information on a microscopic scale in a nondestructive fashion. The second class of techniques exploits the high lateral coherence of modern synchrotron sources, a byproduct of the quest for high brightness or brilliance. We will see that such techniques now push radiology into the submicron scale and the submillisecond time domain. Furthermore, they can be implemented in a tomographic mode, increasing the information and becoming potentially quite useful for the analysis of cultural heritage specimens. http://mdpi.com/1424-8220/8/12/8378/ Tue, 16 Dec 2008 00:00:00 CET Sensors 2008-12-16 8 12 Review 8378 8400 1424-8220 Nondestructive Characterization by Advanced Synchrotron Light Techniques: Spectromicroscopy and Coherent Radiology 2008-12-16 doi: 10.3390/s8128378 Giorgio Margaritondo Yeukuang Hwu Jung Ho Je http://mdpi.com/1424-8220/8/9/5576/ Hyperspectral imaging is a non-destructive optical analysis technique that can for instance be used to obtain information from cultural heritage objects unavailable with conventional colour or multi-spectral photography. This technique can be used to distinguish and recognize materials, to enhance the visibility of faint or obscured features, to detect signs of degradation and study the effect of environmental conditions on the object. We describe the basic concept, working principles, construction and performance of a laboratory instrument specifically developed for the analysis of historical documents. The instrument measures calibrated spectral reflectance images at 70 wavelengths ranging from 365 to 1100 nm (near-ultraviolet, visible and near-infrared). By using a wavelength tunable narrow-bandwidth light-source, the light energy used to illuminate the measured object is minimal, so that any light-induced degradation can be excluded. Basic analysis of the hyperspectral data includes a qualitative comparison of the spectral images and the extraction of quantitative data such as mean spectral reflectance curves and statistical information from user-defined regions-of-interest. More sophisticated mathematical feature extraction and classification techniques can be used to map areas on the document, where different types of ink had been applied or where one ink shows various degrees of degradation. The developed quantitative hyperspectral imager is currently in use by the Nationaal Archief (National Archives of The Netherlands) to study degradation effects of artificial samples and original documents, exposed in their permanent exhibition area or stored in their deposit rooms. http://mdpi.com/1424-8220/8/9/5576/ Thu, 11 Sep 2008 00:00:00 CEST Sensors 2008-09-11 8 9 Article 5576 5618 1424-8220 Quantitative Hyperspectral Reflectance Imaging 2008-09-11 doi: 10.3390/s8095576 Marvin E. Klein Bernard J. Aalderink Roberto Padoan Gerrit de Bruin Ted A.G. Steemers http://mdpi.com/1424-8220/8/3/1984/ Different physical and chemical factors, such as light, temperature, relative humidity, pollutants and so on, can affect works of art on display. Each factor does not act individually, but its effect can be enhanced or accelerated by the presence of other factors. Accordingly, an evaluation of the impact of the whole environment on art objects is recognized as an essential requirement for conservation purposes. To meet the most up-todate guidelines on preventive conservation, in recent years several scientific projects supported by the EC were aimed at developing innovative tools that could complement the standard methods for environmental monitoring in museums. These research projects produced a new generation of passive sensors that are capable of taking into account the overall environmental effects by mimicking in some way the behaviour of real works of art. The main goal of the present paper is to provide a survey of these sensors, which represent a new frontier in the environmental control in museums. Furthermore, the use of optical fibres, as both intrinsic sensors and devices for interrogating sensors, will also be illustrated, and examples of their use in the cultural heritage field will be reported. http://mdpi.com/1424-8220/8/3/1984/ Sat, 22 Mar 2008 00:00:00 CET Sensors 2008-03-22 8 3 Review 1984 2005 1424-8220 Innovative Sensors for Environmental Monitoring in Museums 2008-03-22 doi: 10.3390/s8031984 Mauro Bacci Costanza Cucci Andrea Azelio Mencaglia Anna Grazia Mignani