Optical temperature measurements in shock tubes from relative emission intensities.

A method is presented for obtaining spectroscopic temperatures in shock tubes using relative emission from two wavelength regions of a molecular band system. Experimental results are given for the OH violet system obtained in the reflected wave region near 3500 degrees K. These results show that equilibrium conditions prevail and that the spectroscopic temperatures agree with those calculated from shock wave velocities. A resume of the appropriate theoretical considerations is given along with a detailed discussion of the experimental techniques required. A brief discussion is also given of some other techniques used to measure temperatures in shock tubes, and comments are made regarding these methods as well as on some of the general problems associated with spectroscopic temperature measurements in shock tubes.