At the aim to avoid this problem, the most recent XRF portable instruments are equipped with a fluxing helium gas system that allow the detection of element up to sodium.
A drawback for the portable XRF instruments is the suffering in the detection of “light elements” characterized by an atomic number lover than Silicon.
The main advantages of XRF analysis are: the absolutely not destructive measurement, the short time analysis of samples of any kind, the possibility to use portable XRF instrument.
In relation to physical techniques applied in the field of cultural heritages, the XRF technique is by now a well consolidate technique. The emitted radiation in the near IR and the near UV range is analyzed with a very low spectral resolution of the order of tenths nanometres giving information on the chemical composition of the object under analysis. The atomic spectral lines emitted during the ablation are collected through an optical fibber and analyzed by a spectrometer Echelle type coupled to a ICCD camera. Pulsed laser beams are concentrated in a restricted area of investigation and their interaction with the matter produce the plasma ablation of the stroked zone. In recent years, several research groups have proposed the use of LIBS to obtain information on the sample composition with minimal damage to the artwork. the field of cultural heritages the application of LIBS to determine also in situ the composition of the materials without compromising the integrity of artworks is useful in order to understand the artwork and to plan appropriate conservation and restoration intervention.
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