Two schemes of possible transducer-based six-component standards are presented. The equations describing the functioning of the apparatuses have been formulated and the analysis of the uncertainty has been performed. Thereupon, information on the achievable metrological behaviours and on the criteria to be adopted for designing some of the mechanical elements is provided.

At IMEKO - XV World Congress, the design of the first UK national torque calibration machine was described.
As part of the design of the machine frame, a structured finite element (FE) study was carried out to predict its behaviour. A series of models were created, with varying levels of idealisation. These were used to evaluate the linearity of response to load application, the deflection and stress states under differing load conditions, and dynamic response using both modal and post-dynamic analysis. The effect of using tubular columns in the upper structure in place of solid bars was also modelled.
The study provided confidence in the design of the machine frame and reduced the risk of post-manufacturing changes. It also contributed to the design of the software that controls the application of deadweight masses and the applied torque.
During commissioning of the machine, deflection and frequency measurements will be made to close the design loop and provide validity to the FE analysis.

Electronic balance control of a high precision two-pan flexure-strip mass comparator for double weighing at the UK National Physical Laboratory has been implemented. Critical damping of the freely oscillating loaded beam has been achieved. With a 10 mg differential in 1 kg mass comparisons, steady-state compensation was held for 10 minutes alternatively on either pan, with a stability in mass reading of (standard deviation) 3 parts in 10^-10 of a kilogram. Noise attenuation resulted in signalto- noise ratio of 80 dB on a recovered mass difference signal magnitude of 6 volts dc equating to1 µg in 1 kilogram. The design enables a two-pan balance to be used in single and double weighing mode. The paper briefly outlines previous work on highprecision mass comparators, then outlines the basic system features of the NPL high precision mass comparator and describes the design and performance of the automatic balance control. The work undertaken confirms that the flexure strip balance, with correctly designed and constructed electronic control, forms a superior instrument for accurate measurement of mass (< µg in 1 kg).

The decade series of 10-5-2-2’-1 and 10-5-3-2-1 for submultiples of the unit of mass have been studied to find designs where two comparators are used. The criterion used in finding the designs was to minimize, using the method of least squares, the sum of the absolute values of the elements in the inversion matrices of the normal equations. To date researchers only have reported that when more than one comparator is used in a decade using an orthogonal design for one comparator the orthogonality is lost to produce covariances. However this study has found several cases where orthogonal designs can be used for using two comparators in a decade. The designs could reduce both the nonorthogonality by 50 % and the overall variances by about 45 %. Even though the orthogonal designs are for the case where the ratio of the comparator’s standard deviation is 2, the combination of most comparators could be used with the orthogonal designs.

This paper concerns the development of an entirely new sensor (called Gyroscopic Force Measuring System, or simply called GFMS) for measuring a force vectorially. The principle and the dynamical characteristics of the GFMS for measuring a force vector are analyzed theoretically. Two auxiliary turntables (driven by servomechanisms) are installed around the gyroscope, in which turntables rotate to follow some angles of incidence of a force vector. Some unfavorable errors caused by various factors are analyzed. A compensation method is proposed as a device both for accurate force measurement and disturbance suppression. The feasibility of the proposed GFMS is confirmed by numerical simulations.