A novel hyperspectral imaging system (HI90, Bruker Optics), working in the mid-infrared range and recently developed
for the remote identification and mapping of hazardous compounds, has here been optimized for investigating painting
surfaces. The painting Sestante 10 (1982) by Alberto Burri has been spectrally and spatially investigated with the HI90
system revealing the distribution of inorganic materials constituting the artworks. In order to validate the results
obtainable by the imager for the pigment identification previous tests on laboratory models were performed. Yellow,
white and blue pigments painted with different binders (namely egg, alkyd, acrylic and vinyl) were investigated by the
HI90. Afterwards, the polychrome painting Sestante 10 was investigated focusing the attention on the inorganic material
distribution revealing the presence of different extenders (kaolin, BaSO4, CaSO4) mixed with the various silica-based
pigments present in the painting. The brightness temperature spectra collected by HI90 have also been compared to
single point reflection spectra acquired by a conventional portable FTIR spectrometer (Alpha-R by Bruker Optics)
highlighting the good spectral quality of the imaging system. This comparison permitted also to evaluate the spectral
response and the diagnostic strengths of the spectral range available by the HI90 imaging (1300-860 cm-1), validating the
reliability of the obtained chemical images. This study clearly highlights the high potential of the new hyperspectral
imaging system and opens up new perspectives in the current scientific interest devoted to the application of mapping
and imaging methods for the study of painting surfaces.
In this paper a new compact and portable instrument for combined reflectance, time-resolved and steady-state
fluorescence is presented. All the optical parts of the apparatus, carefully described in the text, were chosen after an
extensive market survey in order to obtain the best performances coupled with the smallest dimensions. This instrument
through the use of a dedicated multiple fiber optic probe, allows the complete photophysical behaviors of investigated
materials to be collected from the same point of the analyzed surface. In this way, the resultant instrumental setup is a
portable device, usable in situ for non destructive and non invasive diagnostic purposes in the field of cultural heritage.
Preliminary results concerning organic dyes characterization, which is the main application of luminescence-based
diagnostic techniques in artworks, are presented and compared with those previously obtained using separate devices.
Concerning reflectance data, improvements in the deep detectable UV spectral range have been achieved switching from
the integrating sphere of the old instrument to bifurcated optical fibers used as probe in the new one. Special attention
was devoted to test the instrument capability in order to obtain the true emission spectrum, corrected for the selfabsorption
effect, for which good results were found. This particular experimental procedure is strongly recommended,
by a diagnostic point of view, to avoid distortions in the instrumental responses, namely the spectral shape and emission
maximum wavelength of a fluorophore as function of the color saturation.