Compression of Mercury at High Pressure

Abstract

An exact method of computing volume changes under high pressure from acoustic‐wave‐velocity measurements is developed. It is applicable to large as well as small compressions. To illustrate the application of the method, precision ultrasonic‐velocity measurements made in mercury at pressures up to 13 kbar for three temperatures have been used to compute V as a function of T and P. The volume is determined to an accuracy of better than 0.01% at each pressure and temperature. An analytical expression for the pressure dependence of the volume in which all coefficients are expressed in terms of the bulk modulus and its derivatives is developed and shown to give a better representation of the P—V data than many of the equations now in use.