TEMPERATURE AND PRESSURE DEPENDENCE OF VELOCITY OF ULTRASOUND IN ARGON

Measurements have been made of the velocity of ultrasound in argon at temperatures ranging from 90 to 165°K and at pressures from 10 to 100 atm. The results have been used to determine the adiabatic compressibility and the ratio of specific heats below the critical point. Above the critical point the minima of the velocity versus pressure curves have been determined. Though they appear to define a curve that is an extension of the vapor pressure curve, these minima become quite indistinct above 160°K. © 1968.