The new test facility for transonic compressor stages TCD2 is based on the know-how gathered by transonic compressor 1. It adopts the basic concept of an open-circle test facility. Air is sucked into the compressor via a settling chamber and a bellmouth. At the compressor outlet the air is guided through a throttle and a collector box and emitted to the ambience. The compressor is driven by a 1,8MW electrical drive. The speed transformation from motor speed to compressor speed is achieved vie a planetary gearbox. Measurement of compressor power and efficiency is performed by a contact-free torque transducer.