EUROMET.M.F-S1: Comparison of force standards between NIS (Egypt) and NPL (United Kingdom)

Abstract

This paper details the results of a bilateral comparison carried out between the national force standard machines of Egypt and the United Kingdom. The results indicate that the uncertainty claims of the two laboratories can, in general, be supported. Recommendations on revised protocols to be used for future comparisons are given.

Intercomparison between deadweight machines in China and UK up to 1 MN

“…For the calculation of the value, the correct uncertainty contributions obtained at the three laboratories must be included in the analysis [3]. The value is defined by equation 1.…”

Calibration and measurement capability evaluation for 1 MN hydraulic force standard machine newly installed at NMIJ

“…Dead-weight type force standard machines (DWMs) use a mass-calibrated deadweight and local gravitational acceleration to provide forces up to 4.4 MN with a calibration and measurement capability (CMC) of 2 × 10 −5 or better (coverage factor of k = 2) [3]. Although several NMIs have introduced MN-class DWMs in recent years [3][4][5][6][7][8], establishing a DWM with a capacity of 500 kN or more requires significant resources. Force standards in this range often involve more complex machines that use smaller deadweights and force amplification via levers and hydraulic piston-cylinders.…”