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.

A hinge measurement flexure calibration set-up for stiffness measurements has been built at the Physikalisch-Technische Bundesanstalt (PTB) to estimate parasitic loads on PTB’s 5 MN·m torque standard machine (TSM). This paper describes the improvements made to a measurement flexure calibration set-up made since its first presentation. The list of measurement uncertainty influences is refined. Initial results of a combined transversal force and bending and torque moment stiffness measurement are presented and compared to a previous finite element analysis.

The redefinition of the kilogram in 2019 in terms of a fixed numerical value of a constant of nature, the Planck constant h, created the opportunity for the realisation of mass at any point on the scale and improvement in the uncertainty at sub gram scales. In this work, part of the route to measurement of mass at small scales at the National Physical Laboratory (NPL) will be described. The aim is to miniaturise a system based on the planned NPL “Next Generation” Kibble balance to a simplified gram level Kibble balance. This is a preparatory step for future work on a micro-electromechanical system (MEMS) scale Kibble balance.

The SI unit of mass, the kilogram, was redefined on 20 May 2019. The new definition is made in terms of the fixed numerical value of the Planck constant, h. The kilogram no longer takes traceability from the International Prototype of the kilogram and therefore a new system of traceability and dissemination must now be established to ensure reliable and repeatable measurements for industry. Two methods of dissemination will be compared and evaluated.