Abstract：A high accuracy 1 mN·m to 1 N·m torque standard machine is newly developed at National Institute of Metrology (NIM). For 1 N·m torque standard machine, the moment-arm system is the key component of the machine, the structure and material of moment-arm concern the accuracy of moment-arm length and affect the technical performance of the machine. The structure design, the material selection and the manufacture and measurement of the moment-arm are introduced, the automatic limit protection component and the software emulation on stress and deformation of the moment-arm are described. The uncertainty of the moment-arm length is evaluated to be 4.2×10-6(k=2), the moment-arm fully meets the requirements of technical performance of 1 N·m torque standard machine.
2016, Vol. 37 
