CALIBRATION SOURCE FOR OH LASER-INDUCED FLUORESCENCE-DENSITY MEASUREMENTS WITH THERMALLY DISSOCIATED H2O IN ATMOSPHERIC AIR

A calibration technique for OH laser-induced fluorescence (LIF) densit y measurements through the use of the thermal dissociation of ambient H2O in an atmospheric air furnace with a tunable KrF laser has been de monstrated. The stable and uniform concentration of OH produced in the furnace permits direct calibration of LIF signals without the uncerta inties associated with reference flames. The presence of OH in atmosph eric air that is heated to temperatures exceeding 1500 K is sufficient for LIF measurements with most OH LIF laser systems. The measured OH density is found to agree well with the computed OH chemical-equilibri um density over a temperature range of 1500-1850 K.