The paper describes the difference in the standards of measurement for weighing indicator. A digital load cell simulator with high resolution for type evaluation of weighing indicators was developed and its traceable calibration was also presented by DC voltage ratio method using a 7.5 digit multimeter with dual channel. The type evaluation method of weighing indicator was investigated and the performance test effect on the indication error was also discussed.

Based on the “force standard machine weights exchange method and weights exchange device” patent technology, a deadweight force standard machine (DWM) of 500 kN was developed. Benefited by the weights exchange control system with eight weights and load frame，this machine can load/unload any load level equally with the minimum increment of 10 kN, in 10 kN to 500 kN range，and the load history curve is basically the same. Eliminating the counter-force phenomenon in traditional DWM, it meets the technical requirements of OIML R 60 international recommendations for loading equipment.

The article describes the possibilities of calibrating the force constant in an electromagnetic force compensation (EMFC) load cell using the electrostatic force compensation principle. The static and dynamic principles of calibration of the Kibble balance for the electrostatic force constant, as well as calibration by means of compensation of the electrostatic force by the electromagnetic force, are considered. The combination of the two compensation principles in the load cell allows the measurement of forces in the range of 20 pN to 2.2 mN and ensures traceability to national standards. The relative uncertainty in the measurement of forces of about 100 nN is estimated to be about 0.001.

This paper describes the new proposal of the calibration of hydraulic torque wrenches. The calibration includes the different metrological effects of the hydraulic torque wrenches like repeatability, reproducibility, and the piston position. A sensitivity analysis is introduced to the different uncertainty contributions of the of hydraulic torque wrenches like the piston position, mounting position and the mechanical adaptation. The measurements show that the piston position has the significant influence on the measurement uncertainty of the calibration result. The uncertainty evaluation of the calibration facility is introduced including the effect of the lateral forces that comes from the application of relatively high torque values with short lever arm lengths. The estimation of the measurement results and the corresponding uncertainty are performed like the calibration standard ISO DIN 51309 without the estimation of the hysteresis. The calibration method and the corresponding validation are accepted from the German DAkkS accreditation body.