Externally pressurized gas journal bearings (EPGJB) are widely adopted to support high speed rotors. This paper presents novel experimental benchmark test data which enables EPGJB model validation. Axial and circumferential pressure profile measurements are presented for a 40 mm diameter annular restrictors EPGJB operating at speeds up to 25 krpm. The corresponding rotor position, air mass flow rate, and load capacity are also measured. The effects of the supply pressure, rotational speed, and load on the measured variables are presented. The measurements are in good agreement with numerical model computations. The cases in which the model deviates from the measured data are discussed in terms of compressible flow theory.