It was determined that the calibration of the photoacoustic spectrometer using known molecular absorption of the laser pulses with an energy of 30 mJ and duration of ~50 ns by atmospheric water vapour and further measurements of aerosol absorption coefficient in the atmospheric air should be carried out at the laser beam radius not less than 1.5 mm. The obtained results are based on the numerical calculations and experimental study of the shape of pressure pulse generated in the atmospheric air depending on the laser beam radius, the nature and duration of the heat release process.
atmospheric air, aerosol absorption, laser photoacoustic spectroscopy technique