Design and Manufacturing of a High Capacity Deadweight Force Standard Machine

Abstract

A deadweight force standard machine is a mechanical structure that generates force by subjecting deadweights to the local gravitational field. Korea Research Institute of Standards and Science (KRISS) maintains several deadweight force machines for national force standards. Recently, KRISS has launched a project to develop a 1 MN deadweight force standard machine. The project is scheduled to be finished in 2014. This paper describes the design of the deadweight force machine. Concept and structure of the force machine are illustrated in the paper. The manufacturing and compensation/calibration of deadweights of the force machine are also described in this paper.

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.…”