Design of a force lever system to allow traceable calibration of MN?m torque in nacelle test benches

The need for torque measurement in the MN?m range in the wind industry is outlined in the following, which also shows the gap between national torque standards and the wishes of the users. Furthermore, a solution to this issue is presented: the design of a force lever system. Such a setup separates the torque load into the two components of force and lever length. Within the European research project Torque measurement in the MN?m range, several design variations have been studied. This paper lists the requirements of a force lever system to be used in nacelle test benches. It also discusses different design variations to fulfil the requirements. These include various force transducers and options to transmit additional mechanical loads through the force lever system. Finally, a system design is presented that fulfils all requirements and can be used for further studies.