Five laser-excited fluorescence methods for measuring spatial flame temperatures 1: Theoretical basis

Abstract

Five methods for measurement of flame temperatures based upon laser-excited fluorescence are discussed with respect to the derived expressions, the assumptions necessary, the advantages, and the disadvantages. The use of each of the five methods for measuring spatial flame volumes ( $⪝1{\text{mm}}^3$) and temporal flame temperatures (corresponding to $⪝1‐\mu \text{sec}$ time period) is given. The five methods consist of one based upon linearity between the fluorescence signal and the laser spectral irradiance, three based upon saturation, and a fifth, which is not critically dependent upon the laser spectral irradiance.