Quantitative measurement of atomic sodium in combustion environments using tunable laser absorption spectroscopy

Accurate detection of sodium is crucial for understanding alkali metal release behavior, which plays a key role in mitigating fouling, slagging, and corrosion in combustion systems. However, existing diagnostic techniques face significant challenges in quantitative measurement with robust performance in complex environments. In this work, a novel quantitative measurement method for atomic sodium based on tunable laser absorption spectroscopy was proposed for the first time, to the best of our knowledge. This technique achieved a detection limit of 0.98 ppb·m and a temporal resolution of 0.1 s. Using this method, the sodium absorption spectrum was found to exhibit minimal temperature dependence from 1300 K to 1800 K. Furthermore, the reliability of this method was validated in a typical complex combustion environment.