Abstract

The theoretical basis of a new technique called thermally assisted atomic fluorescence for measurement of local spatial-temporal flame temperatures is given. In this method, the ratio of fluorescence signals from a radiatively excited level and a higher collisionally excited level or from two higher collisionally excited levels of an inorganic probe, such as In or Tl, is related to the flame temperature. The conditions necessary for the measured flame temperature to be identical to the translational (Boltzmann) flame temperature are given. The experimental system and conditions for making flame temperature measurements, which consists basically of a single pulsed dye laser and a gated detector, are described. The assumption of steady-state conditions is discussed as well as several anomalies in terms of fluorescence from certain energy levels of TI. The accuracy and precision of the measured flame temperatures for several methane-air flames are discussed.

Temperature measurements in flames using thermally assisted laser-induced fluorescence of Ga

Richard G. Joklik, J. J. Horvath, and H. G. Semerjian
Appl. Opt. 30(12) 1497-1504 (1991)

Temperature measurement by two-line laser-saturated OH fluorescence in flames

Robert P. Lucht, Normand M. Laurendeau, and Donald W. Sweeney
Appl. Opt. 21(20) 3729-3735 (1982)

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

J. D. Bradshaw, N. Omenetto, G. Zizak, J. N. Bower, and J. D. Winefordner
Appl. Opt. 19(16) 2709-2716 (1980)

Thermally assisted fluorescence of laser-excited OH A²Σ⁺ as a flame diagnostic tool

A. A. Neuber, J. Janicka, and E. P. Hassel
Appl. Opt. 35(21) 4033-4040 (1996)

Flame temperature measurements using the anomalous fluorescence of pyrene

Diane L. Peterson, Fred E. Lytle, and Normand M. Laurendeau
Appl. Opt. 27(13) 2768-2775 (1988)