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Portable equipments available for the MOLAB access and their features |
 Measurements on the facade of the Cathedral of Huesca, ES.
1.
Scanning IR-colour reflectography - [INOA] EQUIPMENT: The
equipment allows recording colour and IR reflected images free of
optical distortion and with the best resolution presently available in
the field. The system collects simultaneously images corresponding to
four different regions of the electromagnetic spectrum, infrared, red,
green and blue, which can be perfectly superimposed. From the collected
data it is possible compare directly, on the monitor of a PC, the
visible image of the object under study and its IR reflectogram. This
allows users to study the execution technique of a painter and, as in a
recent study of Perugino's technique, clearly identify hand-drawings,
pentimenti, and cartoon re-use. Besides, it is also possible to
identify regions of undocumented restorations or the presence of some
pigments. For this purpose, the imaging survey can be usefully
complemented with punctual spectral analyses carried out by fiber optic
vis-NIR spectroscopy. USE: characterisation of
painting techniques, in panel and wall paintings, through the
identification of underdrawings; identification of undocumented
interventions; characterisation of
pigments. 2. Laser
micro-profilometry - [INOA] EQUIPMENT:
The
laser micro-profilometer is an interferometric device to measure with
high precision the distance between an optical head and the surface of
a wide variety of objects. The optical head is a conoprobe, a device
composed by a birifrangent crystal coupled to two polarizers, placed
between a lens and a CCD camera. The light, diffused by the object
under investigation, is split into two beams which interfere creating a
fringe pattern. The distance comes from the measurement of
the
fringe period. Depending on the lens mounted on the probe, a
micrometric to sub-micrometric resolution is achievable, to the
detriment of a short measurement range. Such a distance-meter, mounted
on a scanning device, allows the relief of small objects or almost flat
surfaces to be measured with very fine details. USE:
Laser
micro-profilometry can be applied to measure and monitor the surface of
many artworks, ranging from wooden panels to characterise possible
undocumented restoration interventions, to any painting to
evidentiate micro colour detachments; to marble artefacts to monitor
the roughness before and after the restoration intervention, to panel
paintings of doubtful attribution to find out drawing technique. 3.Fiber optics
FT-IR - [UNI-PG] EQUIPMENT:
The critical part of the portable FT-IR spectrometer is the probe, made
by chalcogenide glass fibers. The fibers totally absorb radiations
below 900 cm-1, but the region 5000-900 cm-1 is characterised by a
satisfactory signal/noise ratio. This is the "finger print" region for
the identification of many organic polymeric substances and inorganic
salts. A light and manageable equipment combines IR transparent fiber
optics with a compact portable JASCO interferometer, that can be used
even on the scaffold of a restoration yard. A large number of
laboratory-prepared standards allow UNI-PG to optimally use the
technique. USE:
in-situ non-destructive
identification of alterations on stones, mortars and metals,
identification of pigments and binders in paintings; identification of
undocumented restorations. The technique is complementary to
micro-Raman and X-ray fluorescence. 4. Micro-Raman spectroscopy -
[UNI-PG] EQUIPMENT:
A
portable equipment for in situ non-destructive studies of inorganic and
some organic substances on stones, metals or polychrome surfaces is
available. A large collection of standards and specific expertise are
also available. USE:
in-situ non-destructive
identification of alterations on stones, mortars and metals;
identification of pigments in wall paintings. This technique is
complementary to FT-IR and X-ray fluorescence. 5. X-ray
fluorescence - [UNI-PG] EQUIPMENT: This
instrument has a resolution of ~130 eV which is the best presently
available for portable equipments. At UNI-PG the instrument is
available coupled with a specific expertise in inorganic sample
identification. USE:
The instrument can be used
for elemental analyses (elements wth Z>12 ) on stones, metals, wall
and easel paintings, and other objects. This technique is complementary
to FT-IR and micro-Raman spectroscopies. 6. Fiber optics VIS-NIR
spectroscopy - [UNI-PG] EQUIPMENT: A portable
instrument is available to be used as spectrometer and colorimeter.
USE: Colorimetric
measurements and, possibly, identification of pigments. Measurement of
possible colour changing after restoration.
7. Fiber optics UV-VIS fluorescence -
[UNI-PG] EQUIPMENT:
A portable equipment for in situ non-destructive studies of
organic substances on polychrome surfaces is available. USE: in-situ
non-destructive identification of the presence of organic substances
and possibly of their nature. The technique is useful as a first
approach to the study of organic substances and could be also useful to
guide micro-samplings for chromatographic or stratigraphic
studies. 8.Portable
fluorescence system - [OPD] EQUIPMENT:
fluorescence is recorded by a couple of lamps (Lubino model) with a max
emission at 365nm. New lamps are also available with additional filters
to furtherly cut the visible component. As a reference to evaluate the
quality of the image a reflectance spectralon is used. Images are
recorded by a digital Nikon or CCD camera. USE: in-situ
identification of distribution of organic substances, via images. 9.
EUREKA-Mouse? - [UNI-PG] EQUIPMENT:
The portable instrument (Nuclear Magnetic Resonance mobile universal
surface explorer, registered trademark at the University of Aachen
-Eureka project E!2214-MOUSE.) is a unidirectional NMR relaxometer
purposely created for the study of cultural heritage and for NMR
characterisation of unmovable objects. At present, the easily portable
EUREKA-MOUSE?, belonging to UNI-PG, is equipped with a Bruker Minispec
console and a laptop computer. Probeheads are small, inserted within
the magnet and already pretuned (Bruker Biospin?). USE:
The instrument can be used to measure paper or parchment degradation,
wood degradation, detachment of painted surfaces from a wall or other
support, and presence of water in porous stones, frescoes or ceramics.
10. Drilling Resistance
Measurement System - [CNR-ICVBC] EQUIPMENT:
DRMS is a new portable system developed and validated for directly
determining stone mechanical features such as the "hardness" by
measuring its drilling resistance [validated within the European
project HARDROCK:Development of a new measurement method to determine
the superficial hardness of exposed monumental rocks
(SM&T,CT96-2065)]. The force is measured with a monaxial
load
cell (estensimetric transducer) which transform the gauge deformation
into an electrical signal (tension). The load cell deformation is
correlated with the "resistance to penetration" hence to the "stone
cohesion". The measuring unit of the Drilling Resistance (DR) is Kgf
(Newton) with sensitivity of 2.0115E-0,3 (V/V) corresponding
at 1 N
and has 100 N as maximum load. The DRMS has not competitors for its
application in comparative tests "in situ" and it has been suggested as
standard method, to UNI Normal (Italy), for assess the quality
assurance of consolidating treatments. USE: The test
is essentially non-destructive, since stones can be tested, with only
minor patching of holes (ؠ5 mm) on exposed faces. With this system it
resulted possible to determine the cohesion profile of a stone material
based on affordable and sensible data of its mechanical and abrasive
properties. With this tool it is possible to determine either the state
of decay and the consolidating performance (efficiency and depth of
penetration) of applied conservative treatments.
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