The invention discloses a calibration-free
flame atomic ratio detection method based on
laser-induced breakdown
spectroscopy, and relates to the technical field of optical
combustion detection.The calibration-free
flame atomic ratio detection method comprises the steps that a
laser-induced breakdown
spectroscopy system is built; carrying out a
laser-induced breakdown
spectroscopy collection test on the target measurement position of the
flame by adopting a laser-induced breakdown spectroscopy
system to obtain an original spectral
signal; calculating the temperature of the laser-induced
plasma based on the original spectral
signal, and verifying that the laser-induced
plasma is in a local
heat balance state; calculating a partition function of the target atoms in the laser-induced
plasma based on the temperature of the laser-induced plasma and the types of the target atoms; and calculating the flame
atomic ratio based on the original spectral
signal, the laser-induced plasma temperature and the partition function of the target atom in the laser-induced plasma. The method has the advantages that the flame atomic ratio in the wide laser energy range can be accurately measured without depending on a
calibration curve, and meanwhile, the reliability of a measurement result is ensured by verifying the plasma state.