The reference torque wrench is usually calibrated and verified on the reference torque standard machine, then traceability to the deadweight standard machine. This paper describes the method of directly calibrating and verifying the reference torque wrench on the deadweight torque standard machine. Specially tool and adapters are designed, the arm length can be adjusted, and the installation position can be changed according to needs, which fully meets the requirements of German DKD-R 3-7 and Chinese calibration guideline JJG 1103:2014. The differences and similarities between Chinese and German calibration methods are also compared and discussed.

This study investigated the uncertainty evaluation procedure in the dynamic torque realised by a dynamic torque generating machine (DTGM) based on an electromagnetic force under development at NMIJ. The dynamic torque can be generated by changing the applied current. The generated torque can be traceable to the International System of Units (SI) by referring to the national standards of voltage, current, angle, and frequency.

In static force and torque calibrations, the quantity is applied to the given measuring instrument in discrete steps to form a measurement series that usually consists of five to ten values. The corresponding calibration results and uncertainties are then acquired through calculation. During normal use of the instrument, the values measured are often distributed within a range and do not align with the calibrated values. A fitting function is then applied to the result that allows the mechanical quantity to be calculated from the indicated deflection value. The uncertainty associated with this calculation must likewise be calculated using a function defined over the range. This article presents enhanced methods for calculating this function.

This paper proposes a research and development of a non-weight intelligent detection equipment and method for temperature testing of large weighing instruments. By analysis the technical problems currently faced by weighing instruments temperature testing, under the test method and requirements for weighing instruments temperature test in OIML R 134, a design and test method of weighing instruments simulation device is proposed, and the supporting high and low temperature test automatic addition and unloading test equipment is developed. The test results prove that the measurement method solves the technical problems of the high and low temperature test of large weighing instruments, realises the intelligent detection of weighing instruments without weights under the temperature alternating environment, eliminates the impact of weighing instrument creep, and improves the work efficiency of weighing instruments temperature measurement.

1 kN·m universal torque calibration machine with reference torque transducer was established at National Measurement and Calibration Center (SASO / NMCC) in 2019. Torque values are generated over reference torque transducers by means of a servo motor. The machine is equipped with an air bearing and a torque arm mounting component. It is possible to calibrate torque transducer, torque wrench with high accuracy and also hand torque tools with this machine. In this paper, the mechanical structure of the machine and the result of the performances test and uncertainty assessment are described. The relative expanded measurement uncertainty is smaller than 2 × 10^-4.