Determination of the time of V-T,R relaxation of the hydrogen fluoride molecule by the spectrophone method

The paper reports on the use of a phasometric spectrophonic method for determining the HF vibrational relaxation time at 330 K and a HF partial pressure in an argon mixture ranging from 0.03 to 2 torr. Total pressure of the mixture was 20 torr for one series and 8 torr for another series of tests. Data are presented in the form of plots of the spectrophone signal phase shifts and rates of vibrational relaxation as functions of HF partial pressure. The experimental points for the vibrational relaxation rate lie on a straight line passing through the origin, which indicates the complete absence of instrumental phase shift. At 330 K, vibrational relaxation time of HF was measured to be 10 to the minus 8th sec atm.