DESIGN, DEVELOPMENT, AND COMMISSIONING OF A 120 kN DEADWEIGHT FORCE STANDARD MACHINE
Andy Knott
Abstract:
This paper describes the development of a 120 kN deadweight force standard machine and its commissioning in late 2003 / early 2004. The rationale for developing a machine of this capacity is given together with details of its design, focusing in particular on the scalepan and weightstack arrangements. The calibration of the masses is described and an uncertainty budget for the force generated by the machine, resulting in an expanded uncertainty of ±0,001 %, is given. Information on the construction of the machine is also given, as are details of the control system. The results of comparison tests between the machine and NPL’s other deadweight machines, carried out as part of the commissioning procedure, are described. The conclusion is made that the machine will be suitable to act as the pilot machine in a forthcoming CIPM 100 kN Key Comparison.
