Torque traceability examination of calibration laboratories in Korea

Torque is a physical quantity that is related to fastening bolt in various industry fields of assembling. The quality of assembling procedure is highly dependent on the accurate torque control. For the accurate torque measurement and control of torque, each torque transducer in industries should be calibrated using qualified torque calibration system. In Korea, there are 14 calibration laboratories for the torque measuring device. They have their own torque calibration system. Some of them are using deadweight torque calibration machine and the others have unsupported torque generating system using torque arm and masses.To check the reliability of the torque calibration laboratories, a series of round robin measurement was performed by the Korean National Measurement Institute, Korea Research Institute of Standards and Science (KRISS). This paper deals with the round robin measurement to check the traceability in torque in Korea. Two torque transfer standards each having 200 Nm capacity were used for the measurement. Measured value as well as the measured uncertainty of each laboratory was compared with those of KRISS.