Calibration of reference torque wrench by new reference torque standard machine at nim

摘要

The paper describes the calibration of three kinds of reference torque wrenches by the new reference torque standard machine at NIM, which was finished at the end of 2017. The new reference torque standard machine is designed to calibrate the reference torque wrench and torque transducer. The relative expanded uncertainty of this torque standard from 10N·m to 5000N·m is better than 5 ×10~(-4) (k=2).