Thermometry in air by optically exciting the I2Cordes bands

An optical method is described to perform instantaneous thermometry along a line in low-density air seeded with I 2 . Laser-induced fluorescence is generated by exciting the I 2 Cordes bands (D 1 Σ u + ← 1 Σ g + ) with a tunable ArF excimer laser near 193 nm. Temperatures from 295 to 648 K are measured by fitting the I 2 emission spectrum from 188 to 195 nm to a vibrational Boltzmann distribution. Uncertainties for average measurements are typically ±5% (±1σ).