The BIPM watt balance: Improvements and developments

This paper summarizes the various improvements to and new developments for the BIPM watt balance which have been implemented over the past two years. The main distinctive feature of the BIPM apparatus is its capability for simultaneous force and velocity measurements. The fact that all the major components of the apparatus are now available (although not yet necessarily in final form) has enabled crucial tests of this. In addition we expect to soon make a first determination of the Planck constant h, albeit with a relatively large uncertainty.