Calibration procedures for torque measuring devices by using a reference type torque calibration machine at NMIJ

Abstract

NMIJ / AIST has been disseminating the national torque standard to Japanese industry by using deadweight type torque standard machines (DWTSMs). In general, DWTSMs can generate more precise torque than other types of TSMs. On the other hand, the calibration takes much longer time than others. One possible solution is to use a reference type torque calibration machine (RTCM). RTCMs have been developed in some national metrology institutes (NMIs). We have started the development of the first RTCM in the range of 100 mN · m to 10 N · m. In this study, we developed the automatic calibration system of the RTCM and investigated the calibration procedures for a low nominal capacity torque measuring device (TMD). It was found that the calibration could be realised by the RTCM, compared with the reliable DWTSM of rated capacity of 10 N · m at NMIJ.

INTERNAL COMPARISON BETWEEN A REFERENCE TYPE TORQUE CALIBRATION MACHINE AND A 10 N·m DEADWEIGHT TORQUE STANDARD MACHINE

“…𝑆 TSM and 𝑆 RTCM are measurement results for the 10-Nm-DWTSM and the RTCM, respectively. 𝑅𝐷 is the relative deviation expressed by equation (1).…”

“…A reference torque calibration machine (RTCM) has been developed to improve the efficiency of calibration service for torque measuring devices at the National Metrology Institute of Japan (NMIJ), part of the National Institute of Advanced Industrial Science and Technology (AIST) [1]. The nominal capacity of the RTCM is 10 N•m.…”