Torque is one of the derived quantities in the International Measurement Units System (SI), this quantity is used more and more with industrial developing. The measurement accuracy of torque quantity depends on the main factors: accuracy of a “working length” of the arm; uncertainty of the acting force, friction torque of the bearing, .etc. In the world, some countries have their primary torque standard machines to calibrate and adjust lower torque standards and measuring equipment. This article introduces the measurement method for accurate determining a “working length” of the arm in a torque standard machine, and to contribute to improving the accuracy of the torque standard machines.
Keyword
arm length, torque standard, uncertainty of torque standard
