The capabilities of a facility, brought into service to collect data on magnetohydrodynamic (MHD) effects pertinent to liquid-metal-cooled fusion reactor blankets, are presented. The facility, designed to extend significantly the existing data base on liquid metal MHD, employs eutectic NaK as the working fluid in a room-temperature closed loop. The instrumentation system is capable of collecting detailed data on pressure, voltage, and velocity distributions at any axial position within the bore of a 2 Tesla conventional electromagnet. The axial distribution of the magnetic field can be uniform or varying with either rapid or slow spatial variations. The magnet gap dimensions, for the uniform field of 2T, are 15.3 cm high × 0.76 m wide × 1.83 m long. NaK was circulated in December 1984 and the magnet was energized in March 1985. Shakedown tests in a round pipe test section are currently underway.