PHASE-DIAGRAM OF THE A-B TRANSITION OF SUPERFLUID HE-3

We have measured the A-B phase transition temperature of superfluid He -3 at pressures from zero to 29 bars, and in all magnetic fields up to the highest field limit of the B phase (approximately 0.59 Tesla). We have also devised a simple function which accurately describes the en tire pressure-temperature-magnetic field phase diagram of the A-B tran sition. This function intrinsically satisfies all correct asymptotic b ehaviors in the low- and high-field limits. Using thermodynamic identi ties we can measure properties which previously could not be directly measured.