SELECTION OF ABSORPTION-LINES FOR I-2-PLANAR LASER-INDUCED FLUORESCENCE MEASUREMENT OF TEMPERATURE IN A COMPRESSIBLE FLOW

it is very important for I-2-planar laser-induced fluorescence measurement of temperature in a compressible flow to choose a pair of absorption lines appropriate to the temperature range. The method for selection of suitable pairs of absorption lines of It in the transition of B (IIou+)-I-3 (v' = 43) <-- X (1) Sigma(g)(+) (v '' = 0) is described. By the use of many pairs of absorption lines, the temperature dependence of the ratio between the fluorescence signals is calculated theoretically and is also investigated in experiments in which several pairs are applied to determination of the temperature distribution of a supersonic free jet.