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 measure ment of temperature in a compressible flow to choose a pair of absorpt ion lines appropriate to the temperature range. The method for selecti on 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. B y the use of many pairs of absorption lines, the temperature dependenc e of the ratio between the fluorescence signals is calculated theoreti cally and is also investigated in experiments in which several pairs a re applied to determination of the temperature distribution of a super sonic free jet.