| CPC G01N 15/1459 (2013.01) [G01N 15/1434 (2013.01); G01N 2015/0046 (2013.01)] | 13 Claims |

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1. A system(S) for characterising particles in the form of an aerosol in an ambient gas, comprising:
a sampler (E) capable of sampling the ambient gas likely to comprise particles in the form of aerosols;
a device (D) for characterising said particles by laser-induced breakdown spectrometry, the device (D) comprising:
a system (SG) for generating, from the gas coming from the sampler (E), a jet of said particles (JP) in a chamber (CH) with which is associated a means (MP) for pumping the gas present in the chamber in order to create a vacuum in this chamber,
a laser (L) capable of emitting a laser beam (FL) in the form of pulses, with which is associated an optical device (DO) arranged to focus said laser beam in the chamber (CH), perpendicularly to a direction of propagation of the particle jet (JP), to create, in a focal volume (VF), a plasma by the interaction between the laser beam (FL) and the particles (NNP) of the jet, said plasma emitting other particles, characteristics of the interaction between the laser beam and said particles of the jet,
at least one detection device (DD, DD′) comprising a means (MC) for collecting the particles emitted by the plasma and a means (MAS, MAS′) for performing a spectrometric analysis of these particles;
wherein said system(S) further comprises at least one dilution means (MD, MD′) located between a sampling area (ZP) of the sampler (E) for the ambient gas likely to contain particles in aerosol form and the device (D) for characterizing said particles by laser-induced breakdown spectrometry, said at least one dilution means being intended to decrease the concentration of the particles in aerosol form in the ambient gas sampled by the sampler, so that the focal volume (VF) comprises at most one individual particle.
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