A comparison of the electric strengths of hexane vapor and liquid in the critical region

The breakdown strength of gases at low pressures increases regularly with density; using this fact, one can extrapolate the strength of a vapor to densities corresponding to the liquid state. An extrapolation of this type is shown in figure 1 for hexane^1,2, for comparison, point X shows a typical observed value of the strength of the liquid³. As may be seen, the liquid strength is appreciably lower than the extrapolated value. One of the aims of this investigation has been to bridge the gap between these two extremes in density, and to determine whether breakdown strength is a continuous function of density or whether there is a singularity corresponding to the change of phase.