Small pure torque loading method for precise measurement

Measuring instrument becomes more and more compact, which makes miniature precision elastic components-key parts of these instruments-very difficult to manufacture and measure. In measuring process, small pure torque loading is always needed to investigate torsion and hysteresis property of measured object. A loading method for small pure torque was proposed. The loading system is composed of elastic arms, precision rotary table, piezoelectric driver, flexible hinge amplifier, fix shift and strain gauges, which can avoid interference such as friction disturbance, weights swing disturbance existing in conventional loading method. Calibrating process of loading method was given. Calibrating and curve fitting results demonstrate the loading method can meet needed requirements.