Refining and expertly applying experimental techniques for the study of archaeological finds and of historical objects and works of art. These are just some of the skills of CHeLab – the Cultural Heritage Laboratory in the Department of Industrial Engineering (DII) of the University of Trento. Among the different types of samples that CHeLab deals with are ceramic, metal and organic artefacts of interest for archaeological research and artefacts that are the object of study in the history and art sectors. An important area of the Laboratory’s activity is diagnostics, in view of restoration or consolidation interventions.
CHeLab activities are carried out in the framework of research collaborations with national and international partners. In the first place, samples are classified and an information sheet is prepared, complete with photographic documentation, which is also useful in identifying areas for further analysis. At this stage, if necessary, a preliminary microscopy survey is undertaken, mainly using optical microscopes, in order to identify areas of interest more effectively and to guide selective microsampling. Although priority is given to non-destructive investigation methods, it can be important to sample a minimum quantity of material from an artefact, without damaging its integrity, in order to obtain results that are more reliable than those provided by in situ analysis.
On the basis of this preliminary investigation, we produce a matrix of appropriate measures for the characterisation of the samples and for resolving any related problems. At this stage we generally use the investigation techniques available at the Department of Industrial Engineering. The most useful techniques are Fourier Tranform Infrared (FTIR) spectroscopy, and thermal, differential and thermogravimetric analyses. Electron microscopies also have an important role, both scanning (SEM) and transmission (TEM). In both cases the electron microscopes are equipped with systems for energy-dispersive X-ray spectroscopy, which is fundamental for evaluating the chemical composition of the areas under observation. Other extremely useful techniques in this field are X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD). To increase the analytical effectiveness, CHeLab has recently developed novel tools and related methodologies for the acquisition and analysis of data, and these have already been successfully applied, particularly in archaeological studies.
The investigation methods in the cultural heritage field are similar to approaches that can be applied in other fields, such as mineralogical exploration and the characterisation of raw materials. These sectors need to acquire physical and chemical information that is both fast and reliable, preferably with methods that can be used outside the laboratory. These topics are central for several international research projects that the Laboratory’s researchers are actively involved in. One of these is the project SOLSA (Sonic On-Line Sampling Analysis), funded by Horizon 2020, which started in 2016 and which involves a team of ten European partners, including the University of Trento, in designing and developing a multi-analytical instrument to automatically analyse samples extracted during geological survey for mining purposes.
Another field closely linked to cultural heritage, and which CHeLab is actively involved in, is the development of innovative methodologies for environmental monitoring. In this case the particular focus of CHeLab’s work is in the expert application of the aforementioned techniques to samples from envorinmental monitoring stations or systems, looking particularly at atmospheric particulate matter. In addition, to reconstruct past situations and environmental conditions that existed before monitoring programmes began, we have developed strategies that exploit non-conventional environmental proxies able to record atmospheric exposure conditions at different time scales. Methodologies have been developed for sampling based on mosses, pine needles, and incrustations on monuments.