NEW DEVELOPMENTS IN LEVER-AMPLIFIED FORCE STANDARDMACHINES

摘要

This paper describes the unique features and metrological performance of a new 55 kN / 2200 kN lever deadweight force standard machine set up recently at SPRING Singapore. It uses a novel 55 kN deadweight stack with individual mass disk drives, a single lever of 40 times multiplication ratio and a 2,2 MN tension-compression loading device. The machine is of increased capacity, with a wider force range and larger amplification ratio than previously possible. The lever machine covers force range from 10 kN up to 2200 kN in intervals of 10 kN. For the first time, a force standard machine of this type and size uses an entirely digital control system. The machine has been the subject of a comparison measurement with the PTB, preliminary results of which are given. The uncertainties of the machine were found to be within 2?10-5 for the deadweight part and 1?10-4 for the lever part. The system now serves as a primary force standard for Singapore.