Influence of Counterweight-loading on Calibration Result of Reference Torque Wrench using Deadweight Type Torque Calibration Equipment

In a reference torque wrench (RTW) calibration, a counterbalance weight is required to be attached on the torque transducer in order to cancel the torque generated by transducer's weight itself in the case of changing mounting position by rotating the angle of the sensing element with the lever direction when the deadweight type torque calibration equipment having horizontal measurement axis is used for the calibration. In such a case, mass and position of the counterweight and plate must be adjusted depending on the angle of the transducer (the lever direction) because the reaction forces at the loading point of the lever should be as equal as possible in any lever direction. However, it becomes a problem that the comparably large transverse force occurs on the transducer during calibration due to the counterweights and plates . In this research, the influence of the transverse forces on the calibration results of various RTWs was experimentally investigated .